Comma Use in Sentences

Explanation

Use a comma before a coordinating conjunction joining two independent clauses, after a long introductory phrase, and between items in a list. Do not join two independent clauses with a comma alone.

Examples

• We finished the draft, and the editor approved it.
• After a long delay, the train arrived.
• We bought bread, cheese, olives and fruit.

Common mistakes

• We finished the draft, the editor approved it.

  We finished the draft, and the editor approved it.

  A comma alone cannot join clauses.

• After a long delay the train arrived.

  After a long delay, the train arrived.

  Introductory phrases take a comma.

• We bought bread, cheese, olives, and fruit.

  Both are correct; keep the style consistent.

  Serial commas are a style choice.