Overview

In writing, punctuation marks function as signals for your audience. An end mark signals the end of a sentence, requiring a pause before beginning the next sentence. Use the period for declarative or imperative sentences, the question mark for interrogative sentences, and the exclamation point for exclamatory sentences.

Commas signal pauses. Place them between the main clauses of a compound sentence or between coordinate adjectives that precede a noun. Use commas to separate three or more words, phrases, or clauses in a series. Use commas to set off titles of people, references, tag questions, interjections, parenthetical expressions, and conjunctive adverbs. Commas also set off appositives, participles, infinitives, and their phrases if they are not essential to the meaning of the sentence. Use commas to set off an antithetical phrase, or a phrase that uses a word such as not or unlike to qualify what precedes it. Commas also set off introductory prepositional phrases, participles, participial phrases, and adverb clauses.

A semicolon separates main clauses that are not joined by a coordinating conjunction or that are joined by a conjunctive adverb. Semicolons separate items in a series when the items contain commas. A colon introduces a long formal quotation, a list of items, and material that illustrates, explains, or restates preceding material.

In writing, quotation marks tell your audience that someone is speaking. Only direct quotes belong in quotation marks. Use quotation marks to enclose titles of short works, including short poems, essays, magazine articles, book chapters, single episodes of a television series, and songs.

Italics, or underlining, are used to identify the title of a book, a newspaper, a television show, or a film. Italicize foreign words and expressions. Italicize words, letters, and numerals used to represent themselves. Apostrophes signal possession or point out the missing letters in a contraction.

A hyphen divides a word between syllables and joins the parts of compound words. It also joins a proper noun or adjective with a prefix. Hyphenate a fraction used as an adjective or two numerals that indicate a span. A dash indicates a sudden break or change in thought. Dashes may also emphasize supplemental information. Parentheses can be used to set off words that define another word in a sentence or provide other supplemental information.

Certain words can be abbreviated, or shortened, in writing. Abbreviate titles that come before a person's name, like Mrs. Washington or Dr. Pandya. Also, abbreviate words that refer to streets and the names of states on envelopes. In charts and tables, always write numbers as figures. In ordinary sentences, spell out ordinal numbers, numbers that you can write in one or two words, or any number that begins a sentence.