Common Comma Use Errors

Commas: can't live with 'em; can't live without 'em.

Understanding Comma Errors

Commas are punctuation marks that help to clarify the meaning of sentences by separating elements and indicating pauses. However, they are often misused, leading to confusion and ambiguity. In this handout, we will explore some of the most common comma use errors and provide examples to help you avoid them.

1. Comma Splices

A comma splice occurs when two independent clauses (complete sentences) are joined together with just a comma. This is incorrect because a comma alone is not strong enough to hold two independent clauses together.

Example of Comma Splice:

"I went to the store, I bought some milk."

Corrected:

"I went to the store, and I bought some milk." (using a conjunction)

"I went to the store. I bought some milk." (using a period)

"I went to the store; I bought some milk." (using a semicolon)

2. Missing Commas in a Series

When listing three or more items in a series, commas should be used to separate them. The final comma before the conjunction (known as the Oxford comma) is optional but can help to avoid ambiguity.

Example of Missing Commas:

"I bought apples oranges and bananas."

Corrected:

"I bought apples, oranges, and bananas."

3. Misplaced Commas with Adjective Pairs

When two adjectives equally modify a noun, they should be separated by a comma. However, if the adjectives do not equally modify the noun, a comma should not be used.

Example of Misplaced Commas:

"She wore a bright, red dress."

Corrected:

"She wore a bright red dress." (if "bright" modifies "red dress" as a whole)

"She wore a bright, red dress." (if "bright" and "red" independently modify "dress")

4. Commas with Nonessential Elements

Nonessential elements (also known as nonrestrictive clauses), which provide extra information but are not crucial to the meaning of the sentence, should be set off with commas. Omitting these commas can change the meaning of the sentence.

Example of Missing Commas:

"The car that is parked outside is mine."

Corrected:

"The car, which is parked outside, is mine."

5. Incorrect Commas with Subordinate Clauses

Subordinate clauses (dependent clauses) that start a sentence should be followed by a comma. However, when they appear at the end of a sentence, they should not be preceded by a comma.

Example of Incorrect Commas:

"Although it was raining we went for a walk."

"We went for a walk, although it was raining."

Corrected:

"Although it was raining, we went for a walk."

"We went for a walk although it was raining."