5.3 Commas

The rules for commas could fill a course on their own. They are often complicated and confusing. However, to write well you do not need to know all of them. In fact, there are probably only a few people in the world who genuinely do!

So what do commas do? Look at the following sentence:

This is quite a long sentence and is much easier to read and understand if commas are added; they provide structure for the reader so that the meaning is clear:

Like capital letters, it is best to use a comma only when you are sure that one is needed.

If in doubt, leave it out.

With that guidance in mind, there are some key situations that definitely need commas.

One of these is in lists. The commas separate the things in the list. If you don’t use commas the list could be unclear.

For example, look at the difference between these two sentences:

• I went shopping and bought fruit, bread, chocolate, milk and eggs.

• I went shopping and bought fruit bread, chocolate milk and eggs.

Putting the commas in different places changes the things that were bought.

Another situation where commas are needed is when you are adding information to a sentence.

In the example below commas are needed to separate the additional information:

• My best friend Jane unlike me is always late.

• My best friend Jane, unlike me, is always late.