Punctuation: commas in a list

The idea

When you write a list of three or more things in one sentence, commas separate the items so the reader can see where each one starts and ends. Without them, the words run together and the sentence is hard to read.

Put a comma after each item except the last two, which are joined by 'and' (or 'or'). So instead of writing 'red green blue and yellow', you write 'red, green, blue and yellow'.

In British English you normally do not need a comma just before 'and' in a simple list. Read your sentence aloud: a short pause after each item usually shows you exactly where a comma belongs. The same rule also works for a string of adjectives describing one noun, such as 'a hot, sunny, windy day'.

Worked example

Punctuate this sentence correctly: For the picnic we bought rolls cheese grapes and orange juice.

1. Find the list: rolls, cheese, grapes and orange juice are the items bought.
2. Put a comma after each item except the last two, which are joined by 'and'.
3. Do not put a comma before 'and' in this simple British English list.

Answer: For the picnic we bought rolls, cheese, grapes and orange juice.

Watch out

• Forgetting commas altogether, so the list reads as one long string of words.
• Putting a comma between the last item and 'and', or after 'and' itself.