Comma Exercises*
DePauw University Writing Center 

1.  Use commas to set off nonessential modifiers.  A word, phrase or clause that interrupts the normal flow of the sentence without changing the meaning is nonessential or nonrestrictive.  You need a comma both before and after the interrupter.

A.     Clarence, our cat, surprised us with three kittens.

B.     My father, who leads a sheltered life, took a dim view of my being arrested.

C.     My mother, however, saw the injustice involved.

2.  Do not use commas around essential (or restrictive) modifiers. 

A.     All the students who can’t swim must wear life jackets on the canoe outing. (restrictive)

B.     Melvin, who can’t swim, must wear a life jacket on the canoe outing. (nonrestrictive)   

Which rules apply to the following sentences? 

A.  In her essay, “Why I Write,” Joan Didion says that “writing is the act of saying I.”

B.  In her essay, “Why I Write”, Joan Didion…

C.  In her essay “Why I Write,” Joan Didion…

D.  In her essay “Why I Write” Joan Didion… 

3.  Use a comma after any longish introductory element (like a dependent clause or a long phrase) to make the sentence easier to read.

A.     Since we’ve run out of beer, we’ll have to make do with gin.

B.     After all the trouble of sneaking into the movie, Seymour didn’t like the film. 

Even though commas following introductory elements are optional, use a comma if your sentence would be more difficult to read without one. 

4.  A comma precedes a coordination conjunction (and, but, or, for, nor, yet, so) that connects two complete sentences (independent clauses).

A.     Mrytle splashed and swam in the pool, but Marvin only sunned himself and looked bored.

B.     Several women’s rights groups are active today, yet some housewives oppose them.

C.     Clyde went to the library, so he may well be lost in the stacks. 

5.  Use a comma before a phrase or clause tacked on at the end of a sentence.

A.     I just failed another math exam, thanks to Rob’s help at the local tavern.

B.     I just failed another math exam – thanks to Rob’s help at the local tavern

(Note: You can use a dash instead of a comma for greater emphasis.) 

6.  Use a comma to separate a direct quotation from your own words introducing it – if you quote a complete sentence. Omit the commas if you introduce the quotation with “that” or if you quote only a part of a sentence.

A.     F.L. Lucas observes, “Most style is not honest enough.”

B.     F.L. Lucas observes that “Most style is not honest enough.”

C.     F.L. Lucas observes that in writing we are often “not honest enough.” 

7.  Use commas to separate elements in series.

8.  Use commas in dates and to separate dates from the rest of the sentence. 

Eudora, who was born November 15, 1950, in Denver, Colorado, move to Dallas, Texas, before she was old enough to ski. 

9.  Use a comma to separate adjectives in series before a noun if you can insert “and” between them.  Suppose you want to write:

Kitty Clarence has thick short grey striped fur.

Can you say “think and short”?  You can.  Can you say “short and grey”?  Yes.  “Grey and striped”?  Yes.  “Striped and fur”?  No.  You can’t and have it sound right.  So you need only three commas:

Kitty Clarence has thick, short, grey, striped fur.