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Punctuation in referencing

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, Comma

For the main uses of the comma see the Starter Level. The following describes further usage of commas.

To place emphasis

Where you put the comma can emphasise something.


In the 1960s most university students were aged 18-21 and had a grant.

In the 1960s most university students were aged 18-21, and had a grant.

In the second example there is more emphasis on and had a grant, because of the comma before it.

To make definitions clear

If the words which follow a noun define it, there is no comma.

If the words which follow a noun describe it, you do use a comma.

Getting this wrong can really change the meaning. See the example.


My friend who works in Leeds has a nice car.
There is no comma, so who works in Leeds defines my friend. It means - of all my friends, it is the one who works in Leeds who has a nice car.

My friend, who works in Leeds, has a nice car.
With the commas, who works in Leeds describes my friend. It means - my one friend, who happens to work in Leeds, has a nice car.

Towards the start and end of sentences

At the start
You put a comma after any words in the sentence which come before the main part (the first clause which could stand alone).


Therefore, it was too hot to work.

It really helps in using commas if you know about groups of words in sentences. We strongly suggest that you look at the Advice on Making longer sentences in the Main Rules of Written English Development Level.

At the end
You can use a comma to add something to the end of a sentence.


Students often have financial difficulties, for example many have to work part-time to make ends meet.

Using too many commas

You can use so many commas in a sentence that it looks silly and creates confusion.

You do not need a comma for every pause, just for the main ones.


*However, although I did, I think, say I would do that, I'm no longer sure, given that some time has passed, and my memory isn't very good, whether, or not, I did say that.

Although the commas are used correctly, there are so many that by the end you have no idea what it means. It would be better to reword it.

However, although I think I said I would do that, given that some time has passed and my memory isn't very good, I'm no longer sure whether I did say so.

© Learning & Teaching Institute, Sheffield Hallam University 2004