Punctuation marks are symbols that indicate how a text should be read and understood. Punctuation allows writers to organize ideas by signaling pauses, inflection, tone, and intention. Punctuation is used at the end of sentences, within sentences, and within words. This handout provides general guidelines for punctuation, but writers should always tailor their work to their audience, assignment, or citation and formatting style.
End-of-sentence punctuation lets the reader know when a sentence is complete.
A statement (declarative sentence) is followed by a period.
A direct question (interrogative sentence) is followed by a question mark.
Do not use a question mark after a declarative sentence that contains an indirect question.
An exciting or emphatic statement (exclamatory sentence) is followed by an exclamation point.
Use exclamation points sparingly. They can unnecessarily exaggerate sentences or create an informal tone.
Punctuation marks within sentences help combine clauses and emphasize or separate ideas.
Commas give structure to a sentence by separating its parts and indicating where to pause when reading. Within sentences, commas are typically used in the following ways:
Commas are used to separate three or more words or phrases in a series or list.
Commas are used after introductory words or phrases or after an introductory dependent clause (a group of words before the subject of a sentence that does not form a complete sentence by itself).
Commas are used between independent clauses (groups of words with a subject and verb that can stand alone as a sentence) joined by a coordinating conjunction (for, and, nor, but, or, yet, so).
Commas surround nonessential phrases (groups of words that provide optional information).
Semicolons separate clauses or phrases that are closely related and that receive equal emphasis.
Semicolons join independent clauses in a compound sentence with no coordinating conjunction.
After a semicolon, you can add a transition word (conjunctive adverb) to help the sentence’s flow.
Semicolons help avoid confusion in lists where there are commas within the listed items.
Colons follow independent clauses and are used to call attention to the information (word, phrase, clause, or list) that comes after the colon.
Do not use a colon after a verb that directly introduces a list.
A dash can be used to attach material to the end of a sentence when there is a clear break in the sentence or to explain the material preceding the dash.
In the middle of a sentence, paired dashes can function as parentheses or commas by offsetting information.
Parentheses set apart additional or optional information, such as examples or asides.
Parentheses enclose numbers or citations within a sentence.
When parentheses enclose an independent sentence, the end punctuation belongs inside the parentheses.
When parentheses enclose only part of a sentence, the end punctuation belongs outside the parentheses.
Quotation marks enclose the exact words of a person (a direct quotation).
Do not use quotation marks around a paraphrase or a summary of the author’s words.
Quotation marks often surround the titles of articles, poems, reports, and chapters within a book.
The presence of quotation marks influences the placement of other punctuation marks in a sentence.
Place periods and commas inside quotation marks, except when citations follow.
Place semicolons and colons outside quotation marks (if they are not part of the quote).
Place question marks or exclamation pointsinside the quotation marks if they punctuate the quote only.
Place question marks or exclamation pointsoutside the quotation marks if they punctuate the sentence.
Use brackets to indicate changes to an original quote.
The Latin word sic indicates an outdated spelling or error within a quotation that is intentionally left as is. Italicize sic and place it in brackets directly after a misspelling. Alternatively, provide the proper spelling.
An ellipsis consists of three periods according to style: “. . .” (APA, MLA, Chicago) or “…” (AP, fiction).
Ellipses are used in formal writing in place of an omitted word, sentence, or passage within a quotation.
Ellipses are used in fiction writing to suggest a dramatic pause, indicate silence, or allow a sentence to trail off. When a sentence ends with an ellipsis, punctuate normally. (This may result in four consecutive periods.)
Punctuation within words combines words or modifies their function.
Use a hyphen in a compound adjective (or hyphenated adjective) only when the adjective comes before the word it modifies. Some compound adjectives are always hyphenated, such as best-selling.
Use hyphens with the prefixes ex-, self-, and all-; the suffix -elect; and prefixes before proper nouns.
Use hyphens for compound numbers and fractions. When a number is used as a noun, no hyphen is needed.
Apostrophes show possession and form contractions. Do not use an apostrophe with the possessive personal pronouns yours, his, hers, its, ours, their, orwhose.
To show possession, add an apostrophe and an -s to nouns.
Add only an apostrophe for plural possessive nouns ending in -s.
A contraction is a shortened form of two words. Apostrophes show where letters have been omitted.
