Introductory Commas

College students often forget to add an introductory comma to their sentences. 11.5% of college students will forget to add an introductory comma to their sentences, according to a 1988 study (Connors, R. J., & Lunsford, A. A., 1988). An introductory comma introduces an action, a subject, or a previous idea, and makes them easier to see.

Now how do college students know where to find an introductory comma?  Let us explore these three situations.

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Lonely Clause

Some introductory commas are in sentences that start with a lonely clause. A lonely clause is a clause that relies on the other part of the sentence in order to work.

The lonely clauses are underlined in the next two examples. Notice how a comma joins the lonely clause to the rest of the sentence.

• “We will throw you a party, because you want to take time off.”
• “We will work harder, if we want to win.”

An introductory comma comes after a lonely clause. If we change the above examples so that they have the introductory commas, they will look like this.

• “Because you want to take time off, we will throw you a party.”
• “If we want to win, we will work harder.”

The introductory commas are needed because they introduce information in a lonely clause. A lonely clause that has an introductory comma will always start with an adverb such as after, although, as, because, before, if, since, though, until, when, etc. (Lunsford, A., 2008).

Introductory Phrase

An introductory comma also appears after an introductory phrase. An introductory phrase is a phrase that comes before the main subject. Unlike a lonely clause, an introductory phrase lacks the main subject of the sentence.

The introductory phrases are underlined in the next two examples. Notice that the introductory phrases lack the main subject of the sentence.

• “To beat the game and claim the prize, you must understand the rules.”
• “A new person in town, Jake was lost."

Introductory Word

An introductory comma also appears after an introductory word. An introductory word is a word that creates flow from one sentence to another.

• “He tried to think of his opponent’s next move. Meanwhile, his opponent knew he had already won.”
• “Michael Phelps won many Olympic gold medals in swimming. Therefore, he is a good swimmer.”

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Review

When to Use an Introductory Comma

• After a lonely clause that starts a sentence
• After an introductory phrase
• After an introductory word

When to Avoid an Introductory Comma

• The introductory phrase is fewer than five words
• “To get ahead Frank painted the shelves."
• The introductory comma separates the subject from the main verb
• “Quickly he ran to the stop sign realizing that it had fallen.”

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Sources

Want more practice? Check the top of the page for practice problems.