There are some general rules which you can apply when using the comma.
However, you will find that in English there are many other ways to use the comma to add to the meaning of a sentence or to emphasise an item, point or meaning.
Although we are often taught that commas are used to help us add 'breathing spaces' to sentences they are, in fact, more accurately used to organise blocks of thought or logical groupings. Most people will now use commas to ensure that meaning is clear and, despite grammatical rules, will drop the comma if their meaning is retained in the sentence.
A. Using the comma to separate phrases, words, or clauses in lists
1. a series of phrases
- On my birthday I went to the cinema, ate dinner in a restaurant,and went dancing.
2. a series of nouns
- The meal consisted of soup, fish, chicken, dessert and coffee.
3. a series of adjectives
- She was young, beautiful, kind, and intelligent.
Note: if an adjective is modifying another adjective you do not separate them with a comma - e.g. She wore a bright red shirt.
4. a series of verbs
- Tony ran towards me, fell, yelled, and fainted.
5. a series of clauses
- The car smashed into the wall, flipped onto its roof, slid along the road, and finally stopped against a tree.
B. Using the comma to enclose insertions or comments. The comma is placed on either side of the insertion.
- China, one of the most powerful nations on Earth, has a huge population.
C. Use the comma to mark off a participial phrase
- Hearing that her father was in hospital, Jane left work immediately.
D. Use the comma in 'tag questions'
- She lives in Paris, doesn't she?
- We haven't met, have we?
E. Use to mark off interjections like 'please', 'thank you', 'yes', and 'no'
- Yes, I will stay a little longer, thank you.
1. Misplacing a comma can lose friends!
Putting a comma in the wrong place can lead to a sentence with a completely different meaning, look at these two examples:
- I detest liars like you, I believe that honesty is the best policy.
- I detest liars, like you, I believe that honesty is the best policy.