The comma marks a short pause between elements in a sentence.
The comma ( , ) - Easy Learning Grammar
Separating main clausesMain clauses that are joined together with and or but do not normally have a comma before the conjunction unless the two clauses have different subjects.
- You go out of the door and turn immediately left.
- It was cold outside, but we decided to go out for a walk anyway.
Separating subordinate clauses from main clausesCommas are normally used if the subordinate clause comes before the main clause.
- If you have any problems, just call me.
- Just call me if you have any problems.
- We should be able to finish the work by the end of the week,
if nothing unexpected turns up between now and then.
Separating relative clauses from main clausesCommas are used to mark off non-defining relative clauses (see Relative clauses). This is the type of clause that adds to information about a noun or noun phrase.
- My next-door neighbour, who works from home, is keeping an eye on the house while we’re away.
- She moved to Los Angeles, where she was immediately signed as a singer songwriter.
- Let’s make sure the money goes to the people who need it most.
- The computer (that) I borrowed kept on crashing.
Separating items in a listCommas are used to separate three or more items in a list or series.
- She got out bread, butter, and jam (but bread and butter).
- They breed dogs, cats, rabbits and hamsters.
- We did canoeing, climbing and archery.
Separating adjectivesCommas are used between adjectives, whether they come before the noun (i.e. used attributively) or after a linking verb (i.e. used predicatively).
- It was a hot, dry and dusty road.
- It’s wet, cold and windy outside.
With adverbialsWhen an adverbial such as however, therefore or unfortunately modifies a whole sentence, it is separated from the rest of the sentence by a comma.
- However, police would not confirm this rumour.
- Therefore, I try to avoid using the car as much as possible.
With question tags and short responsesCommas are used before question tags and after yes or no in short responses.
- It’s quite cold today, isn’t it?
- He’s up to date with all his injections, isn’t he?
- Are you the mother of these children? – Yes, I am.
- You’re Amy Osborne, aren’t you? – No, I’m not.
With vocativesCommas are used to separate the name of a person or group being addressed from the rest of the sentence.
- And now, ladies and gentlemen, please raise your glasses in a toast to the happy couple.
- Come on, Olivia, be reasonable.
- Dad, can you come and help me, please?
With discourse markersCommas are used to separate discourse markers like Well and Now then from the rest of the sentence.
- Well, believe it or not, I actually passed!
- Now then, let’s see what’s on TV tonight.
- Actually, I quite enjoyed it.
In reported speechCommas are used to follow direct speech (if there is no question or exclamation mark after the quotation), or to show that it comes next.
- ‘I don’t understand this question,’ said Peter.
- Peter said, ‘I don’t understand this question.’
- ‘You’re crazy!’ Claire exclaimed.
- ‘What do you think you’re doing?’ Dad bellowed.
- Peter said: ‘Dream on.’
In datesA comma must be used between the day of the month and the year, when the two numbers are next to each other.
- March 31, 2011