Explainer Video

Tutor: Jonathan



In a nutshell

Commas are used to break up sentences, and make them make more sense. In this lesson you will learn how to recognise and understand the main functions of commas.

Rule 1: Use commas to separate a list

When writing a list, commas are used to separate the items. Put a comma between each item and not each word. You don't need to place a comma between the last two words in the list. Instead use either the word 'and' or 'or' between them.


I need to buy apples, oranges, bananas and pears.

Note: This rule also works for adjectives, which are also known as describing words. As long as the words are describing the same thing, you can use a comma to separate each word except the last two. 


The elephant was big, grey, gentle and graceful. 

Tip: If you can replace each comma in your list with 'and' or 'or', and your sentence still makes sense, then you have used the commas correctly.

Rule 2: Use commas to avoid confusion

Commas are often used to break up a sentence, in order to make the meaning clearer.



It's dinner time. Let's eat Grandma!
This suggests that you are being asked to eat your grandma.
It's dinner time. Let's eat, Grandma!
Using a comma after the word 'eat' changes the meaning of this sentence and makes it clear that you are asking your grandma to eat as it is dinner time.

Rule 3: Use commas to separate clauses

Commas can also be used to separate main clauses from subordinate clauses. The main clause is the core of the sentence. This part of the sentence makes sense on its own. 


Even though it was snowing, we went to the park.

subordinate clause is a part of a sentence that adds additional information to a main clause, but does not make sense on its own. In the sentence above, "Even though it was snowing" is the subordinate clause as it adds further detail to the main clause. If the subordinate clause comes before the main clause in a sentence, use a comma to separate the two clauses. 


Once I had finished my homework, I went to my friend's house.

Rule 4: Use commas to add extra information

Using a pair of commas can help to add extra information in the middle of a sentence.


Kwame's puppy, who is nine weeks old, is very playful.

Fronted adverbials

You can also use commas to join a fronted adverbial to the beginning of a sentence. A fronted adverbial is a phrase at the beginning of a sentence that adds further detail, typically by describing how, when, where or why something was done. The comma is placed after this phrase.


With a great big smile, she accepted the award.

Check your commas

You have used commas correctly if...

  • You can replace the commas in a list with either 'and' or 'or';
  • The information after the comma makes sense on its own;
  • You remove the subordinate clause and the comma, and the main clause makes sense on its own;
  • You remove the pair of commas and extra information in the middle of a sentence, and the sentence still makes sense.

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FAQs - Frequently Asked Questions

How do I use commas to join subordinate and main clauses?

How do I use commas to add fronted adverbials to a sentence?

How do I use commas in a list?


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