Commas After Introductions
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Introductory Clauses
Introductory clauses are dependent clauses that provide background information or "set the stage" for
the main part of the sentence, the independent clause.
For example:
• If they want to win, athletes must exercise
every day. (introductory dependent clause, main
clause)
• Because he kept barking insistently, we threw
the ball for Smokey. (introductory dependent clause,
main clause)
Clue: Introductory clauses start with adverbs like
after, although, as, because, before, if, since,
though, until, when, etc.
Introductory Phrases
Introductory phrases also set the stage for the main
action of the sentence, but they are not complete
clauses. Phrases don't have both a subject and a verb
that are separate from the subject and verb in the
main clause of the sentence. Common introductory
phrases include prepositional phrases, appositive
phrases, participial phrases, infinitive phrases, and
absolute phrases.
• To stay in shape for competition, athletes must
exercise every day. (introductory infinitive phrase,
main clause)
• Barking insistently, Smokey got us to throw his
ball for him. (introductory participial phrase, main
clause)
• A popular and well respected mayor, Bailey was
the clear favorite in the campaign for governor.
(introductory appositive phrase, main clause)
• The wind blowing violently, the townspeople
began to seek shelter. (introductory absolute phrase,
main clause)
• After the adjustment for inflation, real wages
have decreased while corporate profits have grown.
(introductory prepositional phrases, main clause)
Introductory Words
Introductory words like however, still, furthermore,
and meanwhile create continuity from one sentence to
the next.
• The coaches reviewed the game strategy.
Meanwhile, the athletes trained on the Nautilus
equipment.
• Most of the evidence seemed convincing. Still,
the credibility of some witnesses was in question.
When to Use a Comma
Introductory elements often require a comma, but not
always. Use a comma in the following cases:
• after an introductory clause. (Does the
introductory element have a subject and verb of its
own?)
• after a long introductory prepositional phrase
or more than one introductory prepositional phrase.
(Are there more than five words before the main
clause?)
• after introductory verbal phrases, some
appositive phrases, or absolute phrases.
• if there is a distinct pause. (When you read
the sentence aloud, do you find your voice pausing a
moment after the introductory element?)
• to avoid confusion. (Might a reader have to
read the sentence more than once to make sense of it?)
When not to Use a Comma
Some introductory elements don't require a comma, and
sometimes the subject of a sentence looks like an
introductory element but isn't. Do not use a comma in
the following cases:
• after a brief prepositional phrase. (Is it a
single phrase of less than five words?)
• after a restrictive (essential) appositive
phrase. (See our document on appositives at
http://owl.english.purdue.edu/handouts/grammar/g_appos.html.)
• to separate the subject from the predicate.
(See below.)
Each of the following sentences may look like it
requires a comma after the opening segment (marked
with an x), but the opening segment is really the
subject. It's sometimes easy to confuse gerund- or
infinitive-phrase subjects like the following with
nonessential introductory phrases, so be careful. (For
more help with gerunds, see
http://owl.english.purdue.edu/handouts/grammar/g_verbals.html.)
• Preparing and submitting his report to the
committee for evaluation and possible publication[x]
was one of the most difficult tasks Bill had ever
attempted.
• To start a new business without doing market
research and long-term planning in advance[x] would be
foolish.
• Extracting the most profit for the least
expenditure on labor and materials[x] is the primary
goal of a capitalist.
There is an exercise with an answer key. Click here
for he exercise at
http://owl.english.purdue.edu/handouts/grammar/g_commaintEX1.html.
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