Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Use a comma after an introductory clause or phrase
The comma
Punctuation

The most common introductory word groups are clauses and phrases functioning as adverbs. Such word groups usually tell when, where, how, why, or under what conditions the main action of the sentence occurred. (See 49a, 49b, and 49e.)

A comma tells readers that the introductory clause or phrase has come to a close and that the main part of the sentence is about to begin.

EXCEPTION: The comma may be left out after a short adverb clause or phrase if there is no danger of misreading: In no time we were at 2,800 feet.

Sentences also frequently begin with participial phrases that function as adjectives, describing the noun or pronoun immediately following them. The comma tells readers that they are about to learn the identity of the person or thing described; therefore, the comma is usually required even when the phrase is short. (See 49b.)

NOTE: Other introductory word groups include transitional expressions and absolute phrases (see 33f).

EXERCISE 33-1

Add or delete commas where necessary in the following sentences. If a sentence is correct, write “correct” after it. Answers appear in the back of the book.

a. Alisa brought the injured bird home, and fashioned a splint out of Popsicle sticks for its wing.

b. Considered a classic of early animation The Adventures of Prince Achmed used hand-cut silhouettes against colored backgrounds.

c. If you complete the evaluation form and return it within two weeks you will receive a free breakfast during your next stay.

d. After retiring from the New York City Ballet in 1965, legendary dancer Maria Tallchief went on to found the Chicago City Ballet.

e. As an intern, I learned most aspects of the broadcasting industry but I never learned about fundraising.