Punctuation

Tips for Punctuation

End Marks

* Use a period after a declarative or imperative statement:
I went to the library. 
Sign your name here. 

* Use a question mark after a direct question or to indicate uncertainty:
What is your name? 
Chaucer's dates are 1340?–1400.
Do not use a question mark after an indirect question: I asked them what time they were leaving. 

* Use an exclamation point after an exclamatory or emphatic sentence or an interjection:
Give me a break! 
Hey! Ouch! Wow! 

Comma

Use a comma:

* To separate words in a list or series: 
The baby likes grapes, bananas, and cantaloupe. 

* To separate two or more adjectives that come before a noun when and can be substituted without changing the meaning: 
He had a kind, generous nature.
The dog had thick, soft, shiny fur.
Do not use the comma if the adjectives together express a single idea or the noun is a compound made up of an adjective and a noun: 
The kitchen had bright yellow curtains. 
A majestic bald eagle soared overhead. 

* To set off words or phrases in apposition to a noun: 
George Eliot, the great 19th-century novelist, was born in 1819. 
Do not use commas when the appositive word or phrase is essential to the meaning of the sentence: 
The novelist George Eliot was born in 1819. 

* To set off nonessential phrases and clauses: 
My French professor, who has an odd sense of humor, has been teaching for some 30 years. 
Do not use commas when the phrase or clause is essential to the meaning of the sentence: 
The professor who teaches my French class has an odd sense of humor. 

* To separate the independent clauses joined by a coordinating conjunction in a compound sentence: 
He lives in New York, and she lives in London. 
Some people like golf, but others prefer tennis.