We use commas in many different ways:
- To separate items in a list;
- With some conjunctions;
- With non-essential clauses in a sentence;
- To indicate a pause.
We use commas to separate items in a list.
The colours of the flag are red, white, and blue.This example includes a list of three colours. We use a comma between each of the items.
Conjunctions are words we use to join phrases or ideas together. Conjunctions include and, or, but, so, yet, for, and nor.
You use a comma before these conjunctions when they join two independent clauses in one sentence.
I went to watch the fireworks, but I couldn’t see because of the crowd.This sentence has two independent clauses ‘I went to watch the fireworks’ and ‘I couldn’t see because of the crowd’. The clauses are joined by the conjunction ‘but’. Notice the comma before the conjunction.
We use commas at the beginning and end of non-essential clauses (or parenthetical phrases). These clauses often give extra information that is useful, but not necessary.
The wedding dress, which my grandmother made, is on display in the museum.This sentence includes the non-essential clause ‘which my grandmother made’. It provides extra information, but the sentence is still complete without it. Notice the commas before and after this part of the sentence.
Commas generally show where you would pause if you were speaking. We use a shorter pause for a comma than a full stop.
If you are not sure whether to include a comma, try reading the sentence out loud and notice where you pause as you speak.
We use commas after the opening and salutation in a letter.