Punctuation · Commas
Three jobs a comma does — and where it must not go
A comma marks a small pause. In Stage 1 the three jobs you'll be tested on are: separating items in a list, following a fronted adverbial at the start of a sentence, and marking off a clause. Learn the three jobs and the two traps below.
Job 1 Commas in a list
Use a comma between items in a list of three or more. Put and (no comma) before the last item.
I packed apples, pears, grapes and a banana. ✓
Trap: don't put a comma before the final 'and' (in UK schools), and don't use a comma when there are only two items: bread and butter no comma.
Job 1b Lists of actions or descriptions
The list rule also works for verbs and adjectives.
She jumped, twirled, skipped and bowed. ✓
It was a cold, wet, windy morning. ✓
Job 2 After a fronted adverbial
An adverbial tells us when, where or how. When it's moved to the front of the sentence, put a comma after it.
After lunch, we played outside. · Suddenly, the lights went out. · In the morning, it rained. ✓
Clue starters: After…, Before…, Later…, Suddenly…, Slowly…, In the…, At the…, Without warning…, As soon as…
Job 3 To separate clauses
When a sentence starts with a subordinate clause (often beginning with because, although, when, if, as, while), put a comma before the main clause.
Because it was raining, we stayed inside. ✓
Flip test: if the same idea reads naturally the other way round with no comma — "We stayed inside because it was raining." — that's your check that the front part is the clause that needs the comma.
Job 3b Commas for extra information (parenthesis)
A pair of commas can wrap around extra information dropped into the middle of a sentence.
My brother, who is ten, loves football. ✓
If you lift out the part between the commas, the sentence should still make sense: "My brother loves football."
Trap The comma splice
You cannot join two complete sentences with just a comma.
✗ It was late, we went home. · ✓ It was late, so we went home. (or use a full stop)
If both sides could stand alone as sentences, a lone comma is wrong.
The 30-second method
How to crack any comma MCQ fast
- Is it a list of 3+? Commas between items, 'and' before the last (no comma there).
- Does it start with a when/where/how phrase? That's a fronted adverbial — comma straight after it.
- Does it start with because/although/when/if? Comma at the end of that opening clause.
- Read it aloud — a comma marks a natural breath; too many commas usually means wrong.
- Check for a comma splice — two full sentences glued by a comma is always wrong.
10 worked examples
Read the sentence, then the answer with the rule that solves it.
1. I bought milk eggs bread and cheese. Where do commas go?
milk, eggs, bread and cheese — commas between items, none before 'and' (Job 1).
2. After the show we went home.
After the show, we went home. — comma after the fronted adverbial (Job 2).
3. Because she was tired she rested.
Because she was tired, she rested. — comma after the opening clause (Job 3).
4. The cat black and fluffy purred.
The cat, black and fluffy, purred. — commas wrap the extra description (Job 3b).
5. fish and chips — does it need a comma?
No. Only two items, so no comma (Job 1 trap).
6. Suddenly the door slammed.
Suddenly, the door slammed. — comma after the fronted adverbial (Job 2).
7. It was raining, we stayed in.
Wrong — comma splice. Use "It was raining, so we stayed in." or a full stop (Trap).
8. We saw lions tigers and bears.
lions, tigers and bears — list of three, no comma before 'and' (Job 1).
9. When the bell rang the children lined up.
When the bell rang, the children lined up. — comma after the opening clause (Job 3).
10. My teacher Mrs Lee is kind.
My teacher, Mrs Lee, is kind. — commas around the extra information (Job 3b).