Commas, Semicolons, and Colons

When and how to use commas:

• Commas come before coordinating conjunctions (for, and, nor, but, or, yet, so) when they link two independent clauses*:

  It was raining, and I was hurrying to get home.

  She felt terrible, but she went to class anyway. 
  
  

• Commas separate items in a series, including coordinate adjectives:

  He bought bananas, apples, oranges, and cheese.

  She had long, dark, straight, thick hair.
  
  

• Commas set off parenthetical elements such as an appositive, which is a noun phrase or clause that renames or describes the noun directly beside it, and nonrestrictive relative clauses:

  The Washington monument, a massive obelisk, was completed in 1884.
  My parents, who met each other in 1962, have been married for 50 years. 
  
  

• Commas set off transitional phrases: 

  On the other hand, many diets decrease stamina and strength.
  As a matter of fact, American football was derived from rugby.
  Many people, however, are allergic to cats.
  
  

• Commas follow introductory clauses and phrases:

  On the way home, I stopped to buy groceries.

  Because it was raining, I took a taxi home.

  To our surprise, they were brothers.
  
  

• Use commas for direct address, tag questions, mild interjections, and yes/no:

  I hate to say this, John, but this relationship just isn’t working out.
  You like chocolate, don’t you?
  Well, I might have time for lunch with you next week.
  Yes, you must do the homework.
  
  

• Commas indicate direct quoted speech: He said, “Let’s go,” and we did.

  He said we should go, and we did.
  
  

• Commas go inside quotation marks:

  He had heard about “oleo,” but he didn’t know what it was.

   

When and how to use semicolons:

• Semicolons connect two independent clauses that are closely related:

  
  The book is informative; it has helpful charts and graphs.

  My brother is going to Spain for the summer; he will be studying Spanish.
  
  

• Semicolons separate three or more items in a series that already have commas in them:
  
  

  I like big, purple shirts; red, high-heeled shoes; and fluffy, yellow pillows.

  I live with Larry, a student; Moe, an executive; and Curly, a cop.
  
  

• Semicolons separate two independent clauses that are joined by a transition word or phrase:

  
  It is important to get enough sleep; however, too much sleep can be bad for your health.

  Jack did not eat the leftovers in the fridge; instead, he ordered a pizza.
  
  

• Semicolons go outside quotation marks:
  
  

  He had heard about “oleo”; he didn’t know what it was.