Does an introductory clause or phrase need a comma after it?

From LitWiki

"Does an introductory clause or phrase need a comma after it?"

Comma.jpg (Image: Faculty Development and Instructional Design Center, Northern Illinois University)

It is appropriate to use a comma after an introductory a) clause, b) phrase, or c) word that comes before the main clause:

a) Because it was snowing, the flight was delayed.

b) Having completed her work, she went to bed.

c) Yes, you should eat a healthy breakfast.

Use a comma to set off an introductory clause beginning with these frequently used words: after, although, as, because, if, since, when, while.

Use a comma following an introductory phrase that includes: infinitive and participle phrases, nonessential appositive phrases, absolute phrases,and long prepositional phrases.

A comma should be used after an introductory prepositional phrase to avoid misreading: In all, four students failed the class.

In addition, single introductory words should also be followed by a comma: however, well, yes, unfortunately, etc.

W.W. Norton lists a stylistic exception: "To accelerate the pace of their sentences, writers sometimes skip the comma after an introductory adverb or short introductory phrase" (p. 455).[1]

See Also

"Commas After Introductory Clauses and Phrases" (video)

"Using a Comma After an Introductory Element" (video)


External Links

(Additional Sources)

APS Online Style Manual

Purdue OWL