Week 3b. Constituents 3.1-3.4 CAS LX 522 Syntax I

Week 3b. ConstituentsWeek 3b. Constituents

3.1-3.43.1-3.4

CAS LX 522CAS LX 522Syntax ISyntax I

ConstituentsConstituents Sentences are made of Sentences are made of component partscomponent parts, or , or

constituentsconstituents.. Of course, there are the Of course, there are the wordswords, as we’ve , as we’ve

seen, but there is more structure than that.seen, but there is more structure than that. Some words fit together into larger groups, Some words fit together into larger groups,

that function in certain respects as a unit.that function in certain respects as a unit. And those larger groups (constituents) can And those larger groups (constituents) can

themselves be parts of yet larger groups themselves be parts of yet larger groups (constituents). The structure of a sentence is (constituents). The structure of a sentence is hierarchicalhierarchical..

ConstituentsConstituents

The words that make up a sentence The words that make up a sentence like…like… The students did their syntax assignment.The students did their syntax assignment.

……are grouped together into are grouped together into component parts, component parts, constituentsconstituents, which , which function together as a unit.function together as a unit.

Among them, Among them, [the students][the students], the do-, the do-ers, and ers, and [their syntax assignment][their syntax assignment], the , the done. done.

ConstituentsConstituents

Functioning as a unit…Functioning as a unit… The students did The students did their syntax their syntax

assignmentassignment.. The students did The students did the crossword puzzlethe crossword puzzle.. JohnJohn did the crossword puzzle. did the crossword puzzle. The crossword puzzleThe crossword puzzle is what John did. is what John did. **Crossword puzzleCrossword puzzle is what John did is what John did thethe.. John John likeslikes the crossword puzzle. the crossword puzzle. John likes the John likes the jigsawjigsaw puzzle. puzzle. John likes the John likes the theatertheater..

Finding constituentsFinding constituents

How do we find constituents in a How do we find constituents in a sentence? For many of them, we can sentence? For many of them, we can guess, but a guess isn’t evidence. If guess, but a guess isn’t evidence. If sentences and phrases have sentences and phrases have structure, we should be able to test structure, we should be able to test for this structure.for this structure.

Replacement testReplacement test A constituent is a group of words A constituent is a group of words

which function as a unit. If you can which function as a unit. If you can replacereplace part of the sentence with part of the sentence with another constituent (the smallest another constituent (the smallest constituent being a single word), this constituent being a single word), this tells us that the replaced section of tells us that the replaced section of the sentence is a constituent.the sentence is a constituent.

This isn’t foolproof, but it usually This isn’t foolproof, but it usually works if you try to keep the meaning works if you try to keep the meaning as close as possible.as close as possible.

Replacement testReplacement test The students left.The students left. TheyThey left. left.

The studentsThe students is a constituent.is a constituent.

The students ate the sandwiches.The students ate the sandwiches. TheyThey ate the sandwiches. ate the sandwiches. The students ate The students ate themthem.. The students The students dineddined..

[The students] [ate [the sandwiches]].[The students] [ate [the sandwiches]].

Sentence fragment testSentence fragment test Generally, only constituents can be Generally, only constituents can be

used in the fragmentary response to used in the fragmentary response to a question.a question. Who ate the sandwiches?Who ate the sandwiches?

The studentsThe students.. *Students ate the.*Students ate the. What did the students do?What did the students do?

Ate the sandwichesAte the sandwiches.. *Ate the.*Ate the. What did the students eat?What did the students eat?

The sandwichesThe sandwiches.. [The students] [ate [the [The students] [ate [the

sandwiches]].sandwiches]].

Ellipsis testEllipsis test If you can If you can elideelide a string, it qualifies as a a string, it qualifies as a

constituent.constituent. Ellipsis is really deletion of a string from a sentence. Ellipsis is really deletion of a string from a sentence.

Sometimes this is “repaired” by using the verb Sometimes this is “repaired” by using the verb dodo, , something which we will seek to explain at a later point.something which we will seek to explain at a later point.

The students ate the sandwiches.The students ate the sandwiches. The students The students diddid.. But:But:

The students ate.The students ate. *Ate the sandwiches.*Ate the sandwiches.

Warning: Passing a constituency test constitutes Warning: Passing a constituency test constitutes evidence for a constituent. evidence for a constituent. Failing Failing a constituency a constituency test tells you little—there may be other reasons for test tells you little—there may be other reasons for the ungrammaticality.the ungrammaticality.

Movement Movement (topicalization) test(topicalization) test

Sometimes you can “move” a string of Sometimes you can “move” a string of words to the front of a sentence (then words to the front of a sentence (then generally interpreted as the topic of the generally interpreted as the topic of the sentence). When you can, you’ve found a sentence). When you can, you’ve found a constituent.constituent. The sandwiches, the students ate.The sandwiches, the students ate. Eat the sandwiches, the students did.Eat the sandwiches, the students did. The students, they ate the sandwiches.The students, they ate the sandwiches. *Students ate, the the sandwiches.*Students ate, the the sandwiches. *Students, the ate the sandwiches*Students, the ate the sandwiches

Again, failing a constituency test isn’t evidence Again, failing a constituency test isn’t evidence against constituencyagainst constituency!!

Clefting testClefting test

Like the movement test, if you can fit Like the movement test, if you can fit your string into the frame your string into the frame it be X that Sit be X that S (where you move the string (where you move the string XX from from inside inside SS), ), XX is a constituent. is a constituent. It’s the sandwiches that the students ate.It’s the sandwiches that the students ate. It’s the students that ate the sandwiches.It’s the students that ate the sandwiches. It’s eat the sandwiches that the students It’s eat the sandwiches that the students

did.did. *It’s students eat that the the sandwiches.*It’s students eat that the the sandwiches. *It’s students ate that the did the *It’s students ate that the did the

sandwiches.sandwiches.

Finding constituentsFinding constituents

Tests: Replacement, ellipsis, Tests: Replacement, ellipsis, movement, clefting, fragment.movement, clefting, fragment.

Some to try:Some to try: Two African swallows can carry a Two African swallows can carry a

coconut.coconut. A cat was walking down the street.A cat was walking down the street. A creature was stirring up trouble.A creature was stirring up trouble. Flying planes can be dangerous.Flying planes can be dangerous.

And all through the And all through the house…house…

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Trees, hierarchy, and Trees, hierarchy, and constituencyconstituency

[The students] [ate [the sandwiches]][The students] [ate [the sandwiches]]

students ate

sandwichesthe

the

square bracketnotation

tree structure



students ate

sandwichesthe

the

constituentconstituent



students ate

sandwichesthe

the

constituent

The triangleThe triangle Sometimes, when the internal constituency Sometimes, when the internal constituency

is unknown or unimportant to the current is unknown or unimportant to the current discussion, a triangle is used instead.discussion, a triangle is used instead.

the students ate

the sandwiches

TreesTrees

An abstract tree An abstract tree structure…structure…

A

B C

D E

TreesTrees

The “joints” of the tree The “joints” of the tree are are nodesnodes. The nodes . The nodes here are labeled (with here are labeled (with node labelsnode labels).).

A

B C

D E

TreesTrees


Nodes are connected by Nodes are connected by branchesbranches..

A

B C

D E

TreesTrees


Nodes are connected by Nodes are connected by branchesbranches..

The node at the top of the The node at the top of the tree (with no branches tree (with no branches above it) is called the above it) is called the root root nodenode. A is the root node.. A is the root node.

A

B C

D E

TreesTrees

Nodes with no branches Nodes with no branches beneath them are called beneath them are called terminal nodesterminal nodes..

B, D, E are terminal B, D, E are terminal nodes.nodes.

A

B C

D E

TreesTrees

Nodes with no branches Nodes with no branches beneath them are called beneath them are called terminal nodesterminal nodes..

B, D, E are terminal nodes.B, D, E are terminal nodes.

Nodes with branches Nodes with branches beneath them are called beneath them are called nonterminal nodesnonterminal nodes..

A, C are nonterminal A, C are nonterminal nodes.nodes.

A

B C

D E

Tree relationsTree relations

A node X A node X dominatesdominates nodes below it on the nodes below it on the tree; these are the nodes tree; these are the nodes which would be pulled which would be pulled along if you grabbed the along if you grabbed the node X and pulled it off node X and pulled it off of the page.of the page.

A

B C

D E


A node X A node X dominatesdominates nodes below it on the nodes below it on the tree; these are the nodes tree; these are the nodes which would be pulled which would be pulled along if you grabbed the along if you grabbed the node X and pulled it off node X and pulled it off of the page.of the page.

C dominates D and E.C dominates D and E.

A

B C

D E

C

D E


Remind you of anything?Remind you of anything?To briefly reconnect with To briefly reconnect with actual language data, it actual language data, it seems as if you do seems as if you do something to C (like pull something to C (like pull it off the page), it affects it off the page), it affects D and E as a unit.D and E as a unit.

A

B C

D E

C

D E


A set of terminal nodes is A set of terminal nodes is a a constituentconstituent if they are if they are all dominated by the all dominated by the same node and no other same node and no other terminal nodes are terminal nodes are dominated by that node.dominated by that node.

““D E” is a constituent.D E” is a constituent. ““B D” is not.B D” is not.

A

B C

D E

C

D E


A node X A node X immediately immediately dominatesdominates a node Y if X a node Y if X dominates Y and is dominates Y and is connected by only one connected by only one branch.branch.

A immediately dominatesA immediately dominatesB and C.B and C.

A

B C

D E


A node X A node X immediately immediately dominatesdominates a node Y if X a node Y if X dominates Y and is dominates Y and is connected by only one connected by only one branch.branch.

A immediately dominatesA immediately dominatesB and C.B and C.

A is also sometimes called A is also sometimes called the the mother mother of B and C. of B and C.

A

B C

D E


A node which shares the A node which shares the same mother as a node X same mother as a node X is sometimes called the is sometimes called the sistersister of X.of X.

B is the sister of C.B is the sister of C. C is the sister of B.C is the sister of B. D is the sister of E.D is the sister of E.

A

B C

D E

SubstitutionSubstitution One of the ways we know a verb is a verb One of the ways we know a verb is a verb

(category) is by observing that it can (category) is by observing that it can substitute for other verbs.substitute for other verbs. Pat likes to sing. Pat likes to drive.Pat likes to sing. Pat likes to drive. Pat bought a book. *Pat bought (a) sing.Pat bought a book. *Pat bought (a) sing. Pat likes to eat sandwiches.Pat likes to eat sandwiches. *Pat bought eat sandwiches.*Pat bought eat sandwiches.

So is So is eat sandwicheseat sandwiches a verb? a verb? Well, kind of, yes.Well, kind of, yes. It’s a constituent, a phrase, that has the It’s a constituent, a phrase, that has the

properties a verb does. A properties a verb does. A verb phraseverb phrase..

The making of a phraseThe making of a phrase

We’re trying to characterize our We’re trying to characterize our knowledge of syntactic structure.knowledge of syntactic structure.

Our grammatical knowledge is a Our grammatical knowledge is a system (we can judge new sentences).system (we can judge new sentences).

All things being equal, a theory in All things being equal, a theory in which the system is simpler (needed which the system is simpler (needed fewer assumptions) is to be preferred fewer assumptions) is to be preferred over a theory that entails more over a theory that entails more complex one.complex one.

The making of a phraseThe making of a phrase In that spirit, we know that a phrase In that spirit, we know that a phrase

differs from a word in that it differs from a word in that it containscontains words (or other phrases).words (or other phrases).

We’ve seen that when words are We’ve seen that when words are combined into a phrase, the phrase combined into a phrase, the phrase inherits the properties of one of the things inherits the properties of one of the things we combined. (The phrase has a we combined. (The phrase has a headhead).).

Suppose: a Suppose: a phrasephrase can arise from can arise from mergingmerging two words together, with one two words together, with one taking priority. In a way, attaching one taking priority. In a way, attaching one word to another.word to another.

The making of a phraseThe making of a phrase

What will Pat do?What will Pat do? singsing eat sandwicheseat sandwiches

What does Pat like?What does Pat like? to eat sandwichesto eat sandwiches to singto sing

[to [eat sandwiches]][to [eat sandwiches]] So, a phrase can also arise from combining So, a phrase can also arise from combining

toto and a verb phrase, to make a bigger and a verb phrase, to make a bigger phrase.phrase.

MergeMerge So, let’s go for the simplest theory of So, let’s go for the simplest theory of

structure we can (and only move away structure we can (and only move away from it if the simplest theory won’t work).from it if the simplest theory won’t work).

A phrase is a syntactic object formed by A phrase is a syntactic object formed by combining (combining (mergingmerging) two syntactic ) two syntactic objects, with the properties inherited objects, with the properties inherited from one of them (the from one of them (the head head of the of the phrase).phrase).

A word is a syntactic object.A word is a syntactic object.

Merge, in the abstractMerge, in the abstract A good way to A good way to

think about this is think about this is that we have a that we have a number of number of syntactic objects syntactic objects lying around on a lying around on a workbench of workbench of sorts.sorts.

We use the We use the operation Merge operation Merge to assemble them to assemble them together into one together into one syntactic object.syntactic object.

B

D E

Merge, in the abstractMerge, in the abstract We combine D and E We combine D and E

using Merge to form a using Merge to form a combined syntactic combined syntactic object.object.

We need to call our new We need to call our new object something, so we object something, so we call it C.call it C.

C is now a syntactic C is now a syntactic object (containing D & object (containing D & E).E).

D and E are now “off the D and E are now “off the table”—we can’t Merge table”—we can’t Merge D with anything because D with anything because it’s inside C. (“Merge it’s inside C. (“Merge only combines objects at only combines objects at their root nodes”).their root nodes”).

B C

D E

Merge, in the abstractMerge, in the abstract Since C is now a Since C is now a

syntactic object, syntactic object, we can combine we can combine C with the other C with the other syntactic object, syntactic object, B, to form a new B, to form a new syntactic object syntactic object we’ll call A.we’ll call A.

Now, all we’re Now, all we’re left with is the left with is the single syntactic single syntactic object A.object A.

A

B C

D E

Merge, in the abstractMerge, in the abstract When two objects are When two objects are

Merged, one of them Merged, one of them is the is the headhead, the most , the most important one.important one.

The head determines The head determines the properties of the the properties of the constituent— that is, constituent— that is, the features of the the features of the head head projectproject to to become the features become the features of the whole of the whole combined object.combined object.

A

B C

D E

Trees and constituencyTrees and constituency Pat will eat lunch.Pat will eat lunch. Pat will dine.Pat will dine.

eat [V] lunch [N]


eat [V] lunch [N]

?


eat [V] lunch [N]

V

So how do we know So how do we know which is the head?which is the head?

When we Merge two things, one is When we Merge two things, one is the head, and determines the the head, and determines the properties of the resulting syntactic properties of the resulting syntactic object.object.

The next thing we’ll turn to is the The next thing we’ll turn to is the question of how the syntactic system question of how the syntactic system knows which is the head.knows which is the head.

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Week 3b. Constituents 3.1-3.4 CAS LX 522 Syntax I