Punctuation in lists
Punctuation has two main roles to play in the presentation of lists of items.
To separate the items in a list
Punctuation is used to separate the items in the list. The usual way of doing this is to place a comma after each item in the list:
The school has a vegetable garden in which the children grow cabbages, onions, potatoes, and carrots.
The last item in a list is often preceded by the words ‘and’ or ‘or.’ Some writers and publishers always put a comma before the word ‘and’ or ‘or’ but it isn’t wrong to leave it out. The important thing is to be consistent throughout any piece of writing.
If each item in the list is quite long, semicolons can be used instead of commas:
This criticism can be interpreted in various ways: as an attack on Shakespeare’s presumption in challenging the university-educated dramatist; as an accusation of plagiarism; and as an attack on Shakespeare’s plagiarism of Greene.
To introduce a list of items
If the list of items is quite a long one, you also need to use punctuation to introduce it. You can use a colon, as in the example above:
This criticism can be interpreted in various ways: as an attack on Shakespeare’s presumption [etc.].
Alternatively, you could use a long dash:
For the more energetic, there are lots of summer outdoor activities—mountain biking, whale watching, ocean kayaking, windsurfing, and golf.