The nominal shift in semantic-syntactic development

COGNITIVE PSYCHOLOGY 7, 461-479 (1975)

The Nominal Shift in Semantic-Syntactic Development

KATHERINE NELSON

Yale University

Transcripts of 24 spontaneous speech samples from 2-year-old children classified by early Speech Type (Referential or Expressive) and MLU level (above or below 2.5) were analyzed in terms of noun and pronoun use in sentences. At higher MLU levels both more sentences and more pronouns were produced than at lower MLU levels. E children used a balance of nouns and pronouns at both levels. There was a decrease in the use of nouns for R children and an increase for E children. Overall, 47% of all nominals as well as 72% of all nominals used in sentences, were pronouns. There were no major changes with development in either the abstract semantic relations expressed or in the discourse function served. The data were interpreted in terms of two contrasting courses of development, one beginning with a lexical emphasis and the other with a syntactic emphasis, which tend to converge between 2 and 3 years of age.

Recent analyses of children’s early speech have indicated that there are substantial individual differences in the extent to which children employ nouns (Nelson, 1973), noun-phrases and pronouns (Bloom, Lightbown & Hood, in press), in both one-word and multiword utterances. Bloom et al. found that two of the children they studied employed primarily pro-forms in sentential constructions when their mean length of utterance (MLU) level was less than 2.5 morphemes, while the other two children in their sample used primarily nouns in verb relations at similar MLU levels. They also found that the two types of construction converged after 2.5 MLU with children from the pronoun group shifting to greater noun use and children from the noun group shifting to greater pronoun use. They proposed that two strategies were involved, one of which employed constant forms for constant functions, while the other reflected grammatical categories entering into functional relations.

Nelson’s (1973) data were derived primarily from vocabulary acquisition records and showed that one group of children (IV= 10) learned principally nouns at the beginning while another group (N=S) tended to acquire other word classes more frequently (e.g., verbs, adjectives, function words, expressive phrases). A corollary observation in this study was that the children in the latter group (called Expressive) also

Preparation of this article was supported by a grant from the Carnegie Corporation of New York, Reprint requests should be sent to Katherine Nelson, Department of Psychol- ogy, Yale University, New Haven, CT 06510.

461 Copyright @ 1975 by Academic Press, Inc. All rights of reproduction in any form reserved.

462 KATHERINE NELSON

learned and used a large number of phrases and sentences early in the language acquisition period, while the former group (called Referential) did not-they could be described as progressing clearly from a one-word to a two-word stage whereas the Expressive speakers could not be so characterized. In all but the earliest productions, the utterances of the E group were of variable morpheme lengths.

These different patterns of early language use were related to a later difference in lexical performance: At 2 years Referential (R) speakers used significantly larger vocabularies than Expressive (E) speakers. The groups did not differ, however, at 30 months in this respect and they did not differ at either age in terms of length of utterance. There was some evidence that the E speakers were using more pronouns in their early sentences, and the phenomenon therefore appeared similar in some respects to that observed by Bloom et al. The relationship of these patterns to the general process of language acquisition remains unclear, however.

Most investigators have grouped pronouns with other “function” words such as prepositions and determiners. Brown (1973) notes, however, that while pronouns are a small, closed grammatical class like these other word classes, they differ from them in carrying semantic roles like those of N and NP and in being represented in most samples of Stage I (less than 2.0 morphemes) speech. Nonetheless, pronouns have usually been considered a “later” acquisition than nouns, and their role in early sentences has generally been ignored.

One of the reasons for the lack of interest in the early use of pronouns probably stems from the conviction that they should be learned late. For example, it has sometimes been suggested that children have difficulty learning the domains of “I” and “You” because they represent in- terchangeable relative terms whose reference depends upon the point of view of the speaker. I know of no evidence to support this suggestion in general, although it is apparently the case for blind children (S. Fraiberg, personal communication). On the contrary, Brown (1973) notes that “ I,” “you,” “my,” and “it” occur in most samples of stage I speech (apparently in correct contexts) and Nelson’s (1973) data show that 4% of early (presyntactic) vocabularies consisted of pronouns of this kind.

Pronouns present other potential difficulties for the language learner. On the grammatical level, pronouns distinguish cases in English while nouns do not. Thus the child must learn that “I” is nominative, “me” accusative and “my” or “mine” possessive, the latter distinction depending in turn on whether a noun is present in the NP or not. (Again, the adult assumption seems to be that this difficulty confuses the child and leads to widespread use of phrases such as “me do it.” But there appears to be scant evidence for this assumption either-at least in published reports.)

SEMANTIC-SYNTACTIC DEVELOPMENT 463

In addition to these grammatical distinctions specified by pronouns but not by nouns, pronouns also specify explicit semantic distinctions between gender (he - she) and number (he - they; this - these). Although nouns do distinguish plural and singular-and the plural inflec- tion is among those earliest acquired-productive use of plurals is not usually found until stage II or III (above 2.0 MLU) (Brown, 1973) and few nouns encode gender explicitly.

Semantically, pronouns are more general than nouns. They can be said to code a few general grammatical and semantic features such as those just noted, which subdivide the world of people and things along a few dimensions (+ animate, + plural; case role in sentence). Thus, from one point of view-on the assumption that children move from the more general to the more specific-one would expect that pronouns would be among the earliest acquisitions while the more specific nouns would be acquired later. (This would be consistent with a differentiation theory such as Gibson’s (1969) and a semantic feature theory such as Clark’s (1973).) The general “da” (or that) found in the early speech of many children is also consistent with this view.

From an alternative point of view that the child moves from the more specific and concrete to the more general and abstract, pronouns would be expected to be acquired late, after the child had abstracted the relevant features from his concrete vocabulary in order to form general nameable categories. Such a position would be consistent with the theory proposed by Vygotsky (1962), or a mediation theory of concept formation such as the Kendlers (1962).

To my knowledge no one has addressed the question as to the condi- tions under which pronouns are used in normal adult discourse aside from grammatical substitution rules for sentence generation. In general, it seems that adult speakers try to avoid redundant speech; they phrase their sentences in such a way that terms understood from either the linguistic or nonlinguistic context are referred to briefly and nonredun- dantly in pronoun form. Repeating the name of a previously referred to referent is appropriate only when the sentence would otherwise be ambiguous; for emphasis or style; or when the syntactic or semantic environment requires it, as when the noun must take a modifier.

It might seem probable that early child speech would not always avoid redundancy in the way just described for adult speech in that children often appear to name things readily denotable by pronouns, and repeat themselves and others spontaneously or on request. Thus if pronouns are used primarily to avoid redundancy in discourse it would appear that children would not acquire them very early, even though they are highly appropriate to the here and now context of their speech.

There are then bases for expecting either early or late pronoun acquisition and use, and either can be explained on semantic, syntactic, con-


ceptual, or functional grounds. What does in fact occur? If two different courses of acquisition can be discerned, do we need to invoke two different theories of development, or can we resolve the discrepancies in some more general way? It is the purpose of the present analysis to examine this question from the perspective of its relation to the E and R differences in lexical acquisition patterns previously identified within the same longitudinal sample. This paper will examine noun-pronoun use in the speech samples taken from both E and R speakers at 24 and 30 months in an effort to explore the dimensions of the phenomenon and to suggest what its relationship to the general acquisition process might be.

METHOD

The data for this study were derived from transcribed tape recordings of the speech of 18 children who served as subjects in a longitudinal study of language acquisition between one and two and a half years, which is described in greater detail in Nelson (1973). One to two hours of child speech and speech to the child by others in a natural home set- ting were recorded and transcribed at 24 months for all 18 children and at 30 months for 16 of the children. The speech of ten children was classified as Referential (R) on the basis of the predominance of general nominal terms in their first 50-word vocabularies. The speech of eight children was classified as Expressive (E), reflecting early vocabularies that contained fewer nominals and were more personal-social oriented. These classifications were made at an average age of 19 months, that is 5 months prior to the earlier (24-month) samples analyzed here and 11 months prior to the later (30-month) samples, on the average. For the purpose of the present analysis, 24 speech samples of 100 comprehensible utterances each were selected to reflect a balanced selection across ages and sex of child, MLU levels and speech type. Seven MLU levels were defined from 1.0 to 4.5 with a range of 0.5 morphemes each, and transcripts were chosen from each of these levels within each speech group. MLU levels were then collapsed into two groups, Low (1 .O to 2.5) and High (2.5 to 4.5), yielding four subgroups from each of which six transcripts were analyzed, as shown in Table 1. The two MLU groups represent ranges from one-word to slightly beyond Brown’s

TABLE 1 DISTRIBUTION OF SPEECH SAMPLES BY LANGUAGE TYPE, MLU AND SEX

Language type Low MLU High MLU

Referential 6 (4M, 2F) 6 (IM, 5F) Expressive 6 (3M, 3F) 6 (2M, 4F)


Stage I and from his Stage II to Stage V, respectively. The cutting point (2.5) comes at the point where Bloom et al.‘s subjects converged in noun-pronoun usage.

For this analysis, the first 100 comprehensible tillcrances (single 01 multiword) of each child were examined in terms of use of nouns and pronouns in sentence relations or alone. Three major kinds of analysis were undertaken:

(A) Balance and number of types of nouns and pronouns used. Within this analysis are included the number of pronoun types; total number of pronouns (tokens); pronoun type-token ratio (PTTR); number of noun types; total number of nouns (tokens); noun type-token ratio (NTTR); total number of nominals; proportion of nominals that are pronouns; the noun/pronoun ratio (NPR); proportion of all nouns used in sentences; proportion of all pronouns used in sentences; personal-impersonal pronouns.

(B) Syntactic-semantic role played by nominals in sentences. For this purpose, a sentence was defined as a two or more word construction which included a verb relation whether or not a verb was present in the construction. A noun phrase (NP) alone was not considered a sentence. Thus “That [is al ball.” would be classified as a sentence but “The red ball” would not. Several different types of semantic-syntactic role analysis have been devised in recent years, some of them based directly on relations apparent in child speech (e.g., Bloom, 1970; Brown, 1973; Schlesinger, 1971) and others based on presumed underlying case relations found in adult language (e.g., Chafe, 1970, Fillmore, 1968). All reflect a similar set of basic noun-verb relationships. The scheme used here was based on Chafe (1970) only because at the time the analysis was undertaken this seemed to be the clearest and most complete system available. The terms used here should be readily translatable into other systems although the distinctions are in some cases less finely drawn. Chafe’s system is based on the definition of a sentence as “either a verb alone, a verb accompanied by one or more nouns, or a configura- tion of this kind to which one or more coordinate or subordinate verbs have been added” (p. 98), a definition implicitly adopted above in the decision as to which child utterances are deemed to be sentences. Noun roles are defined in terms of the types of verbs (state, process and action) to which they are related and the kind of relationship into which they enter. The following classifications are based on Chafe’s discussion:

Agent-the person or thing1 which instigates the action of an action verb.

’ Chafe does not require that agents be animate.


Patient-the entity which is affected by the action or process or enters into the state expressed by the verb. As implied, this is a very wide-reaching category. In each of the following sentences, dish is the Patient:

The dish is brokkn. The dish broke. Harriet broke the dish.

Only in the last sentence is there an agent, however. It is to be expected that Patients occur more frequently than Agents in natural speech.

Experiencer-the person whose mental experience is expressed in a state or process verb of the experential type such as want, know, like, see, hear, feel, learn.

Beneficiary-the person who is in the transitory or nontransitory possession of a Patient as a result of the action expressed by the verb. Buy, sell, give, find, has are all intrinsically benefactive verbs but other action verbs can take optional beneficiaries as either indirect objects (“Mary knitted Tom a sweater”) or as prepositional phrases (“Mary knitted a sweater for Tom”).

Instrument-the object used to accomplish an action most usually expressed by the prepositional phrase “with . . .“.

Location-Chafe categorizes locative prepositions such as “in,” “on, ’ ’ “under’ ’ as locative state verbs and the locations specified as location nouns in relation to them.

Complement-A complement in Chafe’s system completes or spe- cifies more completely the inherent meaning of the verb, as in such sentences as “Mary sang a song, ” “The children played a game.” The category was used in this analysis also to classify predicate nouns of the type “That’s a bird,” where “that” was categorized as Patient. (The practice here departs from Chafe who classifies “bird” as a predicate noun, a particular kind of derived state verb.) As the great majority of Comple- ments in this analysis were of this type, it should be borne in mind that the category is much broader than that defined by Chafe.

Each noun and pronoun used in a sentence was classified as filling one of these roles. Note that many of the relations expressed in early child speech (negation, recurrence, possesion, attribution) are not necessarily classified here as sentences. This accounts for the apparent discrepancy between the percentage of nouns used in sentences and MLU levels found in the analyses here. Possessuon was classified only in a noun Complement sentence (“That’s mine”) and was included in the Benefi- ciary category.

(C) Discourse function of the noun or pronoun. In this analysis, the attempt was made to determine within the context of the ongoing discourse why a particular noun or pronoun was introduced into the sen-


tence. For pronouns, the use might be implicated by prior specification within the sentence (e.g., “Henry was sure he could do it.“) or in previous sentences (“First Mary ate dinner. Then she went to bed.“). The former use was rare or nonexistent. The latter did occur but infrequently (less than 10% of pronoun usage overall); it was termed Linguistic Use. By far the most common ground for pronoun use was apparent existence of the referent in the child’s environment, or the fact that reference was understood from the nonlinguistic context.2

Noun usage is more complicated. As indicated above, adult speakers appear to avoid redundant use of nouns and to rely on pronouns when the referent is obvious. On this assumption, each use of a noun in discourse must be justified in terms of its linguistic or extra-linguistic function. The following justifications were apparent here:

1. Zdentify referent. This classification was used whenever the child was simply naming a referent either in response to a query from an adult or spontaneously, as in showing a picture book or toys, etc. Although not specifically analyzed here, this category included some instances of strictly linguistic identification as when the adult asked, “Who took you to see Santa Claus?” and the child replied, “Uncle Dave.”

2. Introduce referent. In this case the child went beyond simple naming or classification and included the referent in a comment, where the sentence marked the first introduction (or re-introduction after an interruption) of that referent into the conversation.3

3. Semantic-syntactic reference. Some constructions require the use of nouns rather than pronouns, most notably attributives and possessives. In other cases, the noun is required to avoid linguistic or nonlinguistic ambiguity, e.g., “No I want the ball (not the blocks)” or “After Mary told Sue the story, Sue told Bill.”

The two types of noun function just listed termed Required Ref- erence, that is, required by either the linguistic or the nonlinguistic context.

4. Imitation. Immediate repetition of a noun or a noun in a gram-

2 Of course, in some cases the child might use a pronoun inappropriately when the referent was not derivable from either the linguistic or nonlinguistic context. This happens often in child speech and is the subject of study in the development of role-taking and communication behavior in older children. It was not-and could not be-studied here. In fact, because almost without exception the children were talking about referents immediately apparent, it probably occurred infrequently in these samples.

3 It is interesting that this category accounted for most of the cases where the adult had prolonged difficulty in understanding the child’s speech and therefore required many repetitions by the child. When the topic was understood from the previous conversation poor articulation caused little difficulty, but when a new topic was being introduced greater phonemic precision was necessary for communication.


matical construction used by another was not frequent in this sample, but when it occurred it was categorized as an imitation.

5. Redundant. If a reference could be understood from the prior linguistic context and was not required for semantic or syntactic pur- poses, that is, where a pronoun might well have been used instead, its use was considered to be redundant. Self-repetition was also categorized as redundant. (Self-repetitions were tabulated only once, no matter how long the actual repetitive sequence was.)

These two classifications together formed the larger category of Redundant Reference.

6. Other. Uses whose function could not be determined or which did not fall clearly into any of the categories above were included in this category.

Pronoun definition. In this analysis, pronouns included 30 terms. These included not only all of the standard personal and impersonal terms and demonstratives but also pro-locatives (here, there, where) and such proforms as one, some, someone, something, no one. “Thing,” although often used in ways similar to pronouns, was classified here as a noun.

ANALYSIS

Balance and type of nouns and pronouns used. Table 2 shows the val- ues for the measures of noun-pronoun usage by subgroups and the Pearson product-moment correlation of each variable with MLU (seven levels).

Of interest in this table is the fact that while greater use of pronouns is strongly associated with increasing MLU (r = .790, p < .OOl), the mean number of nouns used is not significantly correlated with MLU. This is reflected also in the negative relationship of the percent of all nominals that were nouns to MLU level.

Note, however, that while both the percentage of nouns used in sentences and the percentage of pronouns used in sentences rises with MLU status, the latter percentage averages 83.3% for all groups, com- pared to only 31.0% for nouns. Further, in contrast to the case for all utterances, the percentage of nominals in sentences that were nouns does not show any overall significant relation to MLU. Pronouns consti- tute on the average 72.3% of all nominals used in sentences, while nouns comprise 27.7% of the sentence total but 53.1% of the overall total. In other words, nouns tend to be used to a much greater extent in nonsen- tential contexts, and pronouns in sentential contexts.

The overall relationships revealed in this table can be summarized as follows:

Pronouns imply sentences.


TABLE 2 NOUN-PRONOUN USE BY MLU LEVEL AND SPEECH PATTERN

Measures of noun-pronoun use in 100 utterances

Low MLU High MLU

E R E R

Mean number nominals Mean number nouns Noun TTR Percent all nouns used in

sentences Mean number pronouns Pronoun TTR Percent all pronouns used

in sentences Percent nouns of all

nominals Percent nouns of all

nominals in sentences Mean number of personal

pronouns Mean number of

impersonal pronouns Personal-impersonal

pronoun ratio

75.2 89.0 130.5 126.2 36.8 63.3 62.5 51.5

.409 .527 S72 .652

17.1 14.8 39.9 52.1 .749*** 38.3 25.7 68.0 74.7 .790***

,282 ,433 .222 .214 - .429*

85.0 63.2 94.0 91.0 .588**

49.8 73.7

20.4 36.2 26.9 27.3 -.056

13.0 5.8 30.7 27.5 .845***

25.3 19.8 38.5 47.0 .552**

,557 ,301 ,824 .648 .628**

48.4 40.4

Correlation with MLU

.884*** ,281 ,431s

- .457*

*p< .05. **p < .Ol.

*** p < .OOl.

Sentences imply pronouns. Longer utterances involve increasing use of both sentences and pronouns.

Consider now, however, the differences between groups shown in Table 2. For this analysis, two-way (MLU x E-R groups) analyses of variance (16 in all) were used to identify statistically significant effects. Looking first at noun usage, it can be seen that while the number of nouns used by Referential speakers declined as MLU increased, the number used by Expressive speakers increased. This was reflected in the analysis which revealed no main effect for either MLU or group, but a significant MLU by E-R interaction (F(1,20) = 5.32, p = .03). In contrast, the mean number of pronouns used shows an overall increase with MLU status and in this case the interaction term was not significant, while the main effect of MLU was (F(1,20) = 22.5, p < .OOl). The overall noun percentage (of all nominals) reflects these combined factors, with the percentage considerably higher for R speakers than E


speakers at the low MLU level but reversing direction at the higher MLU level. Note that the percentage for the E speakers remained almost constant. For this variable, the main effect of MLU was significant at p = .02 (F(1,20) = 6.558) and the interaction was also significant (F(1,20) = 5.58,~ = .03).

But while the two Speech Type groups both increased significantly @ < .OOl) in the proportion of nouns used in sentences with increasing MLU, the E group showed a higher proportion of use of pronouns in sentences than did the R speakers especially at the Low MLU level (Speech Type F(1,20) = 4.11, p = .057; MLU F(1,20) = .008; interaction NS). Figure 1 shows the relative use of nouns and pronouns for all utterances and for sentences by MLU status and speech type.

Bearing in mind the small numbers involved in each cell in these analyses (N = 6), it seems reasonable to conclude that the R speakers in this sample were using more nouns overall as well as more nouns in sentences at the Low level of MLU (less than 2.5 morphemes) than were the E speakers, and that the E speakers rather consistantly used pronouns and used these pronouns in sentences. In other words, the E speakers at the Low level spoke more like the more advanced speakers of both groups (more pronouns and more sentences) and they showed little change in these characteristics with change in MLU status.

A different relation between E and R speakers is found in the number of noun types used and the type-token ratios. R speakers used many more noun types than did E speakers, at the Low level, reflecting their larger vocabularies. For this variable, all three sources of variance were significant (Speech Type F(1,30) = 7.02, p = .02; MLU F(1,20) = 13.28, p = .002; Interaction F(1,20) = 13.68, p = .002). While R speakers used more nouns overall, their type-token ratios as shown in Table 1 also reflected greater variety in addition to greater

100

90 c

LOW MLU “(6” HLU

FIG. 1. Percent of pronouns used at two MLU levels.


TABLE 3

FREQUENCY OF PRONOUNS USED BY EACH SPEECH GROUP

Low MLU High MLU

E R

Personal pronouns I You he/she him/her me who us/let’s mine

To::

64 (5) 2 (2) 1 (1) 0 (0) 2 (1) 2 (1) 0 (0) 7 (2) 0 (0)

78

16 (3) 3 (2) 2 (2) 6 (2) 4 (2) 4 (1) 0 (0) 0 (0) 0 (0)

35

E R

102 (6) 23 (4) 15 (5) 14 (3) 12 (3) 2 (2) 3 (2) 2 (2) 4 (3)

177 I

59 (6) 17 (6) 5.5 (4) 3 (3) 4 (2) 9 (5)

14 (3) 1 (1) 3 (2)

165

Impersonal pronouns this/that(s) 69 (6) 62 (6) 87 (6) here/there 31 (6) 28 (5) 42 (6) it(s) 23 (6) 12 (5) 41 (5) what/which 12 (6) 9 (1) 25 (5) one/someone 2 (2) 5 (2) 18 (6) where 2 (1) 0 (0) 6 (4) them 2 (1) 2 (1) 4 (2) they 2 (1) 0 (0) 2 (2)

These/those 5 (2) 1 (1) 3 (3) other forms 4 (4) 0 (0) 3 (1)

Total 152 119 231

Note. Number in parentheses is number of children who used form out of 6.

93 (6) 59 (6) 45 (6) 34 (6) 18 (3) 10 (4) 6 (4) 9 (2) 2 (1) 6 (5)

282

numbers. The Speech Type F for this variable did not reach the .05 level (F = 3.64, p = .07), however.

There was no comparable difference between groups in regard to pronoun types. Note, however, that pronoun TTRs dropped with development, reflecting the fact that the class of pronouns is a small closed set, and as pronoun use rises the ratio of types to tokens must fall. No such limit applies to the indefinitely expansible class of nouns, however.

Table 3 shows the number of children using each pronoun by group and the total number of cases of use. Note that “I” is the most frequently used personal pronoun and is exceeded in use only by the combined category “this/that.” However, as noted above, overall impersonal pronouns were far more frequent than personal. The variety of forms used even at the low MLU levels is striking. The relative frequencies here indicate that the semantically less complex forms are used earlier and more often, with objective (him, her and me) and plural


TABLE 4 SEMANTIC ROLES EXPRESSED BY NOUNS AND PRONOUNS IN SENTENCES

Low MLU

E R

High MLU Correlation

E R with MLU

Mean number of Agents Patients Experiencers Beneficiaries Instruments Locatives Complements

Mean percent sentences with Agents Patients Experiencers Beneficiaries Instruments Locatives Complements

Mean percent pronouns of all Agents Patients Experiencers Beneficiaries Instruments Locatives Complements

3.00 3.83 13.67 18.33 .719*** 17.33 12.33 35.67 34.33 .790*** 8.00 1.33 11.33 6.67 .353

.67 1.17 3.83 3.83 .684*** 0.0 0.0 .17 .17 .340 6.67 5.67 12.83 16.50 .476* 4.33 4.33 11.67 14.33 .559**

9.3 22.3 13.3 18.0 -.054 42.7 37.3 38.6 37.8 .014 14.2 8.1 14.7 7.1 .031 1.7 2.4 3.7 4.1 .455* 0.0 0.0 0.1 0.2 .303

19.6 22.5 15.5 17.8 -.278 12.4 7.4 13.9 15.1 ,243

71.1 53.0 89.8 90.0 78.6 59.9 73.9 73.4

100.0 56.3 85.4 80.8 50.0 66.7 60.1 95.8 0.0 0.0 0.0 0.0

82.9 89.8 70.6 73.7 78.6 14.1 39.7 42.1

.453* -.120 -.OOl

.398 -

-.339 -.276

* p < .05. ** p < .Ol.

***p < .OOl.

forms (us, we, they, them, these) as well as forms involving gender (he, she, him, his) occurring rarely at the lower MLU level and less frequently than nominal singulars at the high MLU level. “I” is apparently mastered before “you” or “he/she.” Errors of usage could not be tabulated accurately in this count, unfortunately, but the frequencies of use show a consistent developmental trend.

The predominance of personal pronouns among E speakers as well as both E and R high MLU speakers could reflect a difference in the content of their speech (more objective vs. more subjective as implied by the E-R labels) or it could reflect a difference in sentence formation and use with more personal pronouns being used as agents and experi- enters while more impersonal pronouns are used as patients and complements. This factor is considered in the next section.

Semantic roles in sentences. Table 4 shows the mean number of sen-


tences containing a nominal in each semantic role, the mean percent of all sentences that expressed this relation, and the percentage of all nominals in that relation that were pronouns, for each speech type and MLU level separately. It also shows the correlation of MLU (7 levels) with each variable. Again two way (MLU x Speech Type) analyses of variance were performed on each variable (21 in all) to identify statistically significant effects.

First consider the relations that change consistently with increasing MLU. There are more sentences with agents by a factor of four among the higher group; there are more than twice as many patients, three times as many beneficiaries, and two to three times as many locatives and complements. Each of these is fairly consistent within and across groups, and each shows a main effect of MLU level at the p = .02 level or less. On the other hand, the Expressive sentences at both levels contain more Experiencers, and the proportion of sentences with these roles is constant for both groups at both MLU levels. The group difference here might help to account for the greater proportion of personal pronouns found among the E group. It should be noted, however, that E sentences contain a lower proportion of Agents at both MLU levels, compensating to some extent for the higher proportion of Experiencers. However, these trends are suggestive only. The difference in proportion of Agents by Speech Type approached significance (F(1,20) = 3.89, p < .063), but neither the absolute number nor the proportional difference in Experiencers did.

When the proportion of all sentences containing a given relation is considered in terms of MLU levels, there are few discernible changes, suggesting that the basic semantic roles are expressed to the same extent in early sentences as in later ones. The low proportion of beneficiaries and the almost non-existent Instrumental class are worth noting. Both appear to replicate findings in other analyses (cf., Bloom et al., 1975; Brown, 1973).

The data in Table 3 are in contrast with Bloom et al.‘s finding that agents tend to be expressed as pronouns and objects affected (patients here) as nouns. Although the first is clearly true, patients here are realized as pronouns more than half the time for all groups and almost three-fourths of the time among E speakers and both high MLU groups. In fact, among both Low MLU groups more patients than agents are realized as pronouns. These differences may, however, reflect the fact that the patient class includes a wider range than does object-affected. In noun-complement constructions, for example, the subject is classified as patient, although it would not, presumably, be classified as an object affected. Experiencers are, as expected, largely pronouns. There were no exceptions to the general child-rule that both agents and experiencers were either personal pronouns or animate nouns, principally people.

An interesting contrast between speech types is again seen here in the


relative use of pronouns and nouns in the various roles. With the exception of the small Beneficiary class the percentage of pronouns used at the Higher MLU levels is comparable across groups. Consider, however, the difference between the two language groups at the Lower MLU level. Here the general rule is that Expressive speakers realize all relations at least 70% of the time as pronouns while Referential speakers use pronouns less than 60% of the time, and always less than the E group. (The exceptions to this rule are the small group of Beneficiary sentences and the Locatives, which, as noted above, show other contrary trends in both proportions used and in the decline of pronouns used overall.) Speech Type was a significant main effect for the proportion of pronouns used in the complement position (@ = .015) and approached significance for experiencers 01 = .068). Complements also showed a significant interaction of Language Type by MLU @ = .Ol)

This analysis then reinforces the more general picture in underlining the predominant use of pronouns in sentential relations with increasing language development and the predominant use of pronouns at all MLU levels by E speakers. Both groups expressed similar semantic relations to similar degrees, except for the marginal difference in the use of Agents by R speakers and Experiencers by E speakers.

Function of nouns and pronouns in discourse. The relation of MLU status and language group to the function of nouns in the context of the conversation-that is, why a noun rather than a pronoun was used-is shown in Table 5. The most striking thing here is that 50% of the noun use by children at the Low MLU level in the R group was for identifying pictures, objects or events, whether spontaneously or in response to an elicitation by the adult. This was twice as frequent as the equivalent

TABLE 5 DISCOURSE FUNCTION OF NOUNS AND PRONOUNS

Mean percent of

Low MLU High MLU

E R E It

Nouns Identification Introduction Semantic-Syntactic Imitation Redundancy Other

Pronouns Linguistic Nonlinguistic

24.8 50.4 33.5 33.8 13.8 18.9 25.8 25.1 21.9 8.8 18.4 24.4

6.9 11.8 11.0 7.3 12.3 7.0 6.3 7.7 20.2 7.4 5.2 1.7

1.2 5.8 12.8 12.7 98.7 94.2 87.2 87.2

Note. Totals do not add to 100% because of rounding errors.


Low-E group. Both groups converged on the use of nouns for identification about 33% of the time at the High MLU level; this represents a drop for the R speakers and a rise for the E speakers. High use for identification can be considered an immature use, as most such referents are obvious to both speaker and hearer and the only function of uttering the noun is to display knowledge of a rather elementary sort. However, this use reflects a common mother-child identification game which may play an important role in vocabulary learning.

The percentage of use for introducing a referent to the conversation or to use it in required semantic or syntactic context rose with development as expected, so that at the higher levels these two uses accounted for 47% of the cases of noun use overall. An Analysis of Variance for the combined variables showed that the main effect of MLU was significant at the .05 level (F(1,20) = 4.27).

There was a relatively low level of redundant use (other than redundant identification and imitation) in sentences for all groups, which is consonant with the findings of high pronoun use in sentences at all levels, although, as noted above, it might be surprising that children should so early be able to utilize the language appropriately in this way.

The only category which showed an overall significant correlation with MLU was the “Other” category, including noun uses which defied classification because the reference or the context was unclear.

The other interesting relation in this table is the use of pronouns for linguistic rather than non-linguistic reasons, that is, when the noun referent has been referred to in the same or a prior sentence. For both groups this use rises to about 13% of the cases, perhaps not impressive, but a minor indication of increasing sophistication of discourse and of knowledge of the possibility of using pronouns not only in their general reference role (where any object can be “it”) but in their specific prior referent-tag role. The MLU effect for this variable was significant at the .02 level (F(1,20) = 6.09).

DISCUSSION

The preceding analyses of 24 speech samples at 24 and 30 months classified by MLU (1.0 to 2.5 and 2.5 to 4.5) and Speech Type (Referen- tial and Expressive) has revealed two different developmental trends which can be summarized as follows:

Referential speakers begin with a high proportion of nouns to pronouns in both their early sentences and in all utterances taken together. They name the objects that they are talking about and their speech reflects a variety of different concepts as reflected in their high noun TTR’s. Although their sentences (constructions involving verb relationships) utilize pronouns almost as frequently as nouns, such constructions are not dominant in their early speech. Rather, modifiers-ad-


jectives and possessives-or the “primitive” functions of ostension, recurrence, disappearance, mark their short multi-word constructions. Their early language could be said to be strongly semantic-even lexical. Their developmental course is toward increasing use of pronouns and correlatively of pronouns in sentences. As this development proceeds, pronouns become predominant in their language use, and the absolute number of nouns used drops.

Expressive speakers begin with a balance of noun-pronoun use, within and out of sentences. Their use of pronouns changes very little with development. However, there is a striking increase in their use of nouns. For these children, little change is seen in the number or kind of semantic relations expressed or the forms used to express them, but there is a change in the number and variety of lexical forms used. Their language becomes increasingly lexical.

A general conclusion drawn from these data is that sentences imply pronoun use, at least for young children. There are a number of reasons for this, including the fact that the conversation of young children is largely concerned with a domain that is clear to all and does not need to be specified by naming. Noun use is largely redundant in this context; pronouns carry the weight of the sentence meaning.

A related conclusion must be that there is no general discernible move either from the specific to the general or from the general to the specific reflected in the language acquisition patterns found here. Rather children appear to make use of both general and specific terms as suits their needs, and depending upon the specificity of what they wish to express, and as Brown (1958) pointed out, what the language provides them with.

The function of nouns within the context of child speech is conceptual or lexical-the specification of a domain of meaning for different words. Referential children concentrate on this function at the outset-they learn to name and acquire large vocabularies reflecting well-differen- tiated conceptual domains.

Pronouns, unlike nouns, carry relational and grammatical meaning in themselves, but only very general lexical or conceptual meaning. In fact, the pronoun system incorporates relatively complex relational and grammatical information, as noted earlier, such as gender, number and case role. Unfortunately, the data do not permit an analysis of how well these specifications were met in actual use in the present speech samples. The high frequency of a few general terms (I, that, it, there) incorporating few of these features, however, indicates that this complex meaning structure was probably not part of the child’s early pronoun system. These general terms can however be used to express semantic relationships in syntactic form with minimal specification of lexical information. Their use is therefore not only appropriate to the child’s here and now language, but it is also functional in enabling the child to acquire sentence frames and forms without burdening him with excessive lexical


information. It therefore allows the child to concentrate on relationships in his communications rather than the specific concepts entering into those relations.

For example, consider the first 10 “sentences” uttered by one of the children in this sample:

I do You do I want it I don’t want it Do it Don’t do it I love you I don’t know What do you want? Go away

These “sentences” are probably acquired as wholes rather than being constructed from their parts. But notice that the use of pronouns (and the pro-verb “do”) enables the child to acquire and use productively and appropriately a much greater variety of sentences expressing relationships of self and others to objects than are usually found in early (two-word) utterances (e.g., Brown, 1973).

This child (and E speakers in general) is, however, temporarily defi- cient in terms of lexical content. There are no content words in her sentences-only general “dummy” terms that can stand for any object, person or action. This child may be advanced in syntax, and therefore in the variety and complexity of the relationships she can express in language even though she must eventually break down these frames for more productive uses (cf. Clark, 1974, on the acquisition and breaking apart of patterned wholes in child language). However, she exhibits little knowledge of the particulars that can fill these slots, and this knowledge must be acquired later.

These facts may be interpreted in several ways. If they are viewed in terms of possible strategies for learning and using the parent language, the following propositions are consistent with them:

(1) Children come to language with a set of underlying concepts of objects and events which reflect the relationships of things to action, consequences of action, location, possession, and salient attributes.

(2) Children may learn names for the objects that enter into and organize these conceptual relations. Such words when used will express the object in one of its relationships. Early sentences may be formed from these concepts by expressing a non-implicit concept relation in conjunction with the object name (Nelson, 1974). Referential speech follows this course.

(3) Children may learn instead-or in addition-forms for the relations into which the central concept enters. Instead of learning object


names they may learn relational words and general dummy terms that stand for any object or action or person, plus sentence frames that express important and recurrent relations. Expressive speech seems to follow this course.

These two possibilities are complementary but are incomplete by themselves. With one strategy the child can elaborate conceptual domains and particular relations in the language. With the other, he can elaborate the conceptual framework itself. Both strategies, however, are realizations of the general process involved in mapping language onto ex- isting conceptual structures.

Several observations follow from this. First, the central role of pronoun use should be emphasized. The advantage of pronoun use is that it reduces the information load of a sentence so that the syntactic-semantic relation can be expressed more completely and complexly. The disad- vantage is that pronouns by themselves cannot be used informatively or in displaced speech. The child cannot communicate about things and events not immediately apparent using only “I,” “they,” “mine,” and “do.”

Second, the hypothesis can be advanced that syntax (in its simple forms) can be acquired easily and virtually independently of specific lexical terms if dummy terms are used. In fact, it-may be that this learning is characteristic of all children at some time but that for many (most of those who have thus far been studied in detail) it is preceded by a lexical stage.4 This proposal should not be interpreted to mean that the child can acquire syntax without semantics or reference. (Recent studies by Moeser and Olson, 1974, have in fact given support to the intuitively reasonable hypothesis that reference is a necessary prerequisite to syntactic learning.) Rather, the child can learn syntactic forms to express semantic relationships among things (so long as those things are present) before learning the specific lexical terms for the things that enter into those relations.

Third, the “two-word” stage which has been studied so intensively is not universal but is one dominant path followed by a large number of children. It probably reflects the child’s construction of simple semantic relationships between words, rather than syntax (cf. Bowerman, 1973). The same semantic relationships will be expressed when syntactic forms are learned from the parent model language, but they will be expressed differently, using more dummy terms and more complete sentence frames, as the alternative syntax-first course does earlier. After such frames are acquired the child can insert the previously learned, more in- formative terms, into them.

4 Relevant to this claim is the apparent ease with which children acquire grammatical and semantic features for pronouns before they acquire similar features for nouns. This phenomenon deserves further investigation.


The hypothesis advanced here is that the differences between E and R developmental patterns represent early cognitive styles or ways of ap- proaching the language learning task. In fact, it should be emphasized, they are not discrete types at all but rather represent different points along a continuum of greater or lesser lexical-syntactic emphasis. For the student of language development, the important point is that significant individual differences may exist even in the acquisition of basic structures, but that these differences themselves may help to elucidate the basic underlying processes, much as the study of different languages leads to the identification of linguistic universals.

REFERENCES Bloom, L. Language development: Form and function in emerging grammar. Cambridge,

MA: MIT Press, 1970. Bloom, L., Lightbown, P., & Hood, L. Structure and variation in child language. Mono-

graphs of the Society for Research in Child Development, 1975 (No. 2), in press. Bowerman, M. Ear/y syntactic development. Cambridge, MA: Harvard University Press,

1973. Brown, R. How shall a thing be called? Psychological Review, 1958, 65, 14-21. Brown, R. A$rst Ianguage: The ear/y stages. Cambridge, MA: Harvard University Press,

1973. Chafe, W. L. Meaning and the structure of language. Chicago, IL: University of Chicago

Press, 1970. Clark, E. V. What’s in a word: On the child’s acquisition of semantics in his first lan-

guage. In T. E. Moore (Ed.), Cognitive development and the acquisition oflanguage. New York: Academic Press, 1973.

Clark, R. Performing without competence. Journal of Child Language, 1974, 1, l-10.

Fillmore, C. J. The case for case. In E. Bach & R. Harms (Eds.), Universals in linguistic theory. New York: Holt, Rinehart & Winston, 1968.

Gibson, E. J. Principles of perceptual learning and development. New York: Appleton- Century-Crofts, 1969.

Kendler, H. H., & Kendler, T. S. Vertical and horizontal processes in problem solving. Psychological Review, 1962, 62, 1-16.

Moeser, S. D., & Olson, A. J. The role of reference in children’s acquisition of a minature artificial language. Journal of Experimental Child Psychology, 1974, 17, 204-218.

Nelson, K. Structure and strategy in learning to talk. Monographs of the Society for Research in Child Development, 1973, 38, (l-2, Serial No. 149).

Nelson, K. Concept, word and sentence: Interrelations in acquisition and development. Psychological Review, 1974, 81, 267-285.

Nelson, K. Some attributes of adjectives used by young children. Cognition, in press. Schlesinger, I. M. Production of utterances and language acquisition. In D. I. Slobin (Ed.),

The ontogenesis of grammar, a theoretical symposium. New York: Academic Press, 1971.

Vygotsky, L. S. Thought and language. Translated by E. Hanfman & G. Vakar. Cam- bridge, MA: MIT Press, 1962.

(Accepted February 14, 1975.)

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The nominal shift in semantic-syntactic development