Quick Punctuation Guide

Comma

Use • before a coordinating conjunction linking main clauses

• following introductory clauses and phrases

• between items in a series

• to set off incidental comments (appositives, nonrestrictive clauses)

• when meaning is unclear without its use

• when authority figures tell you to use one while you are writing for them

Don't use• a single comma between a subject and its

verb

• when a subordinate clause follows a main clause

• before the first or after the last item in a series

• between two words joined by a coordinating conjunction

Semicolon

Use • instead of a coordinating conjunction between

main clauses

• to separate main groups of items in a list already using commas

Don't use• too frequently in the same document

• between parts of unequal grammatical rank

Colon

Use • to connect explanation, details, or a quotation

to a main clause

Don't use• more than one in a sentence

• directly after prepositions or verbs unless you knowingly choose to violate the normal usage rules

Dash

Use • to indicate a sudden change of tone or idea

• to emphasize, clarify, or interject

Don't use• too often

• a hyphen(-) for a dash; dash(--) = two consecutive hyphens or an em-dash

Parentheses

Use • to insert nonessential material

• to indicate citation

• to introduce acronyms, abbreviations, etc.

Don't use• if the material can be better incorporated

another way

Brackets

Use • to interpolate in quotations

• as parentheses inside parentheses

Ellipsis

Use • to indicate an omission

Don't use• to indicate that you're starting a sentence in

the middle

• to alter meaning in a quotation

Apostrophe

Use • to indicate possessive case for nouns and indefinite

pronouns

• to indicate omissions in contractions

• to indicate plurals of odd words, acronyms, and numerals (opt.)

Don't use• to indicate possessive case for personal pronouns

• to add an "s" for making standard words plural

Single Quotation Marks

Use• within double quotation marks or for unusual

terms

Don't use• to pretend you're not really using a word

you're using

Double Quotation Marks Use

• to enclose direct quotes• for minor (internal) titles• correctly with other marks:

• place period and comma inside• place colon and semicolon outside• place question mark and exclamation point inside when

they apply only to the quoted matter, and • outside when they apply to the whole sentence

Don't use• to pretend you're not really using a cliche you're using

Hyphens

Use * • to integrate words into a functional unit

• when your keyboard lacks bullets to set off listed items

Prepositional Phrases

Prepositions connect nouns or pronouns to other words. • The phrases created by this linkage are called

prepositional phrases, and they usually function as modifiers— adjectives or adverbs—adding detail to the sentence.

• Tree frogs are colorful.

• Tree frogs of the Colombian mountain ranges to the north of the country's capital near the border are colorful, with markings on their limbs, between their eyes, underneath their arms, and on their backs in hues of red, orange, green, purple, and black.

Prepositional phrases consist of a preposition, which can be a word or a phrase, and its object:

• Prepositions Objects• according to Aristotle

• because of jellyfishes' sensitivity

• since the beginning

• with regard to ecological studies

• with the exception of white whales

• throughout the article

Lists of prepositions can be found in any grammar book :

• above, • around, • across, • below,• between, • by, • over, • past, • since,• throughout,• concerning,• despite,• etc.

Technical writers tend to use prepositions frequently because they often need to communicate details: • describing specific features of animals,

• analyzing the particular configurations of chemicals,

• explaining the effects of procedures, and

• the like.

However, overuse of prepositional phrases confuses, rather than clarifying, the writer's point.

• The design of the apparatus with the tubing and the electrical wiring was useful for diagnosis of the transmission of electrical impulses in the nerve tested.

Revising to avoid overuse of prepositional phrases makes the ideas and information • more readable,

• easier to understand, and

• easier to retain.

Consider using the object of the preposition as an adjective or converting the idea into a subordinate clause.