Language
Commas with clauses
Put the comma where a clause needs one — after a clause that comes first, around an extra piece of information, and between two main clauses joined by a joining word.
A comma is not a place to breathe. It is a signal about structure, and once you can see the clauses in a sentence, three rules cover almost every comma you will ever need.
Rule one: front clause, comma
When a clause beginning with when, because, although, if or after comes first, a comma closes it. When the rain stopped, we went out. Put the same clause at the end and the comma disappears: We went out when the rain stopped.
Rule two: two main clauses, comma before the joining word
Each half could stand alone as a sentence, so the comma goes in front of and, but or so. It was late, so we took a taxi. Notice this is the opposite of rule one — here the comma comes before the joining word, not after the clause.
Rule three: extra information, commas at both ends
Our neighbor, who is a nurse, works nights. Lift the middle out and the sentence still stands: Our neighbor works nights. That is the test — if it lifts out cleanly and the sentence still points at the same person or thing, it needs a comma at each end — extra information takes commas; words that pick out which one is meant take none, never just one.
The comma that cannot do the job
The bell rang, the children ran out. Two whole sentences held together by nothing but a comma — and a comma is not strong enough. Use a period, or add a joining word: The bell rang, and the children ran out.
Worked example
Punctuate: "Although the bus was late we still reached the ground before the match began".
Find the main clause — the part that could stand alone. We still reached the ground.
Everything else in the sentence is hanging off this, and the commas mark where.
Try it together
Let us punctuate three sentences together, one rule at a time.
The three sentences, all unpunctuated: (1) When the bell rang the hall emptied. (2) The hall emptied but the lights stayed on. (3) Our hall which was built long ago has no windows.
1.Sentence one. Write the one word the comma should come straight after.
Have a go
Write the one word the comma should come straight after: "After the guests had gone we cleared the tables."
Ready to practice?
Eight questions on what you have just read. Nothing is timed, and you can play as many times as you like.