Commas

Commas in a list or series

Generally speaking, when listing items in a sentence, use a comma between the list items but not before the final and or or: 

Wrong: Toddlers like to play with crayons, playdough, and puzzles.

Right: Toddlers like to play with crayons, playdough and puzzles.

Sometimes, when some or all of the items in a list consist of more than one word, a comma after the final and or or can help to avoid ambiguity: 

This style guide can be used by writers, researchers, quality assurers, content managers, and web producers and optimisers.

Commas after introductory words, phrases and clauses

If the introductory phrase is short and there can be no possibility of ambiguity, a comma is not necessary: 

First change your baby’s nappy.

If in doubt contact your doctor.

On some occasions your baby might enjoy massage.

Commas after subordinate clauses

Use a comma after subordinate clauses when they start a sentence: 

After you've changed your baby’s nappy, put baby down to sleep.

Because toddlers are still learning about emotions, they often have tantrums.

When your child shows you something, give them your full attention.

Commas between coordinate clauses

If the clauses are long, have their own subjects and are joined by a coordinating conjunction, use a comma to separate them: 

Australia has one of the fastest growing rates of obesity, but the Australian Government is resisting tighter regulations on food advertising to children.

Note: sentences are best kept short, so it might be better to rewrite a long complicated sentence as two separate, simple sentences.

Commas with non-defining and defining clauses and phrases

Use commas to set apart non-defining clauses and phrases: 

Our website, which is seen here, is one of the most important initiatives in recent years.

Do not use commas with defining clauses and phrases:

All the experts who work with raisingchildren.net.au are excellent.

(The meaning would be different if you changed this to ‘All the experts, who work with raisingchildren.net.au, are excellent’.)

Commas with 'for example'

'For example' is always followed by a comma.

When ‘for example’ is used at the end of a sentence, it's usually preceded by a spaced en dash and followed by a comma:

Trust your child’s judgment – for example, when they ask to try a new sport.

When ‘for example’ is used in the middle of a sentence, it's usually preceded by a spaced en dash and followed by a comma (This construction is best avoided, though, because it's quite complex and might be more difficult for users with low literacy to understand):

Your health professional – for example, your child and family health nurse – measures these things regularly and marks the measurements on the graph.

‘For example’ can also appear at the beginning of a standalone sentence, still followed by a comma:

For example, it’s a good idea to let your child choose between a red t-shirt and a blue t-shirt.