Different Uses for the Comma in English Grammar

In English, commas are always used after introductory clauses and phrases, to join independent clauses, to show interruptions in a sentence, with non-restrictive clauses and phrase, and between modifiers or items in a list. Commas are also used with quotations, addresses, dates, numbers and locations.

The comma is the most frequently used punctuation in the English language, and it is also the most misused punctuation. Some writers and editors have different rules on the usage of commas; some like to use a lot of commas, whereas other texts may have next to none.

Sometimes, commas are necessary to show the exact meaning of the sentence, and without wouldn’t make sense. Look at the two following sentences:

• Because I wanted to help, Richard, I stopped the car.
• Because I wanted to help Richard, I stopped the car.

In the first sentence, the commas show that Richard is being addressed. In the second sentence, Richard is the object of the help.

To Join Independent Clauses

When joining independent clauses with coordinating conjunctions, the conjunctions are usually preceded with a comma, but if the clauses you are joining are short, you may want to leave the comma out. This all depends on, as the writer, if you want to indicate a pause.

• He wanted to go to the cinema, but he wasn’t sure if he could afford it.
• The book lacks the excitement I need, and I thought the characters were lacking emotion.
• The sky was clear and the night was cold.

After Introductory Clauses

After an adverbial clause is used to start a sentence, it is customary to include a comma. This is essential if the clause is quite lengthy.

• When she walked into the room, we stopped talking about her.
• When you get to the house, take the first door on the left to get to the kitchen.

There seems to be a trend for light punctuation in English text today, so with this in mind, you can leave the comma out of the introductory clause, but only as long as it doesn’t cause confusion.

• When he arrived we stopped talking.

By leaving out a comma, you may accidentally portray the wrong message:

• When we were cooking the children had a lot of fun.
• When we were cooking, the children had a lot of fun.

The first sentence (without a comma) makes it look as though you literally cooked the children!

Restrictive And Non-restrictive Clauses

A restrictive clause is a clause that restricts, defines or limits the subject of the sentence; a non-restrictive clause is one that doesn’t narrow the meaning of the subject, but instead adds extra information.

• The man who arrived yesterday went to the church.
• The man, who arrived yesterday, went to the church.

The first sentence is an example of a restrictive clause, whereas the second sentence is an example of a non-restrictive clause.

Using restrictive clauses and non-restrictive clauses changes the meaning of the sentence:

• The women at the factory who went on holiday were fired.
• The women at the factory, who went on holiday, were fired.

As the first sentence is restrictive, only the women who went on holiday were fired. The second sentence is non-restrictive; therefore, all the women at the factory were fired.

In English, commas have lots of different uses. Knowing when, how and where to use them will make your writing much easier to read and understand.