Purdue University North Central Writing Center Handout

Using Commas After Introductions

Readers need commas to separate introductory material from the

main clause.  These commas are placed after...

INTRODUCTORY CLAUSES

Example: If you have read the book, you may find the

movie disappointing.

Clue: Does the sentence start with an adverb such as

After                   If

Although             Since

As                       Though

Because              Until

Before                When

INTRODUCTORY PHRASES

Example: To stay in shape, athletes must exercise

every day.

Clue: Does the sentence start with an infinitive form

of the verb (to + verb), a gerund (verb + ing),

or a preposition (to, on, around, etc.)?

INTRODUCTORY WORDS

Example: However, he may not return until tomorrow.

Use commas after introductory clauses, phrases, and words...

   ...if the introduction is long (are there more than five or

six words before the main clause?)

   ...if there is a distinct voice pause (when you read the sentence aloud, do you find your voice pausing a moment after the introductory part?)

   ...if it is necessary to avoid confusion (is there a possibility that you might have to read the sentence more than once to have it make sense?)