Punctuation 3 - The Comma
The comma is very widely used in English, but its use is commonly misunderstood.
It is simply used to show the reader when to pause, as in normal speech.
Incorrect use of a comma can change the meaning of a sentence, so care must be taken.
Note: Commas cannot be used to join two ideas to form a sentence without a conjunction.
- I was hungry, I ate a sandwich. - INCORRECT!
- I was hungry, so I ate a sandwich. - CORRECT.
This will be discussed in more detail in the section on sentences.
There are over 12 situations when the COMMA is used:
1) Commas are used in lists, between each element, except for the last two.
- "I bought some apples, oranges, bananas and grapes."
2) The word 'However' is an adverb, which is often used at the beginning of a sentence. In such cases, it has to be followed by a comma.
- 'I love chocolate. However, it is very fattening.'
It is also used for other such adverbs, like Therefore, Nevertheless, Moreover, Furthermore, and Still.
This is also true if instead of an adverb an adverbial phrase is used.
- If it was up to me, I wouldn't go. ('If it was up to me' is an adverbial phrase.)
3) Commas are used in sentences when extra information is given:
- My brother, who plays football, lives in London. ('who plays football' is extra information, and needs a comma on either side.)
If, without the information, the sentence made no sense, commas are not needed.
- The man who lives there bought my car. (without 'who lives there', the sentences makes no sense, so no commas are needed.)
4) A comma is used in conditional sentences, if they start with the conditional part.
- 'If you study, you will pass the exam.
If the conditional part comes second, no comma is used:
- You will pass the exam if you study.
5) Commas are used when a noun follows more than one adjective, but only if changing the order of the adjectives does not change the sense of the sentence.
- The big,red,shiny apple fell off the tree. (Notice there is no comma after the last adjective.)
If changing the order of the adjectives affects the logic of the sentence, no commas are used.
- 'I met five pretty French girls yesterday.' doesn't mean the same as 'I met French pretty five girls yesterday.', so no commas are used.
6) A comma is used to separate the month from the year in a date.
- I was born on the 5th of April, 1969.
7) A comma is used to separate the city from the country in a geographical location.
- I was born in London, England.
8) When writing letters, a comma is used at the end of the opening and closing greeting.
- Dear Sir,
- Yours faithfully,
9) In Europe, which includes the U.K., commas are often used as decimal points.
- The rate of inflation is 2,5%.
10) Again in Europe, commas are used as separators for big numbers.
- The population increased from 300,000,000 to 400,000,000.
11) Commas are used when two ideas are combined in a sentence using a conjunction, and the comma goes
before the conjunction.
- I like football, but I don't like rugby.
12) Commas are used before question tags.
- You like pasta, don't you?
Commas play an important role when complex sentences are created, but their use will not be discussed here. There is a separate section on sentence creation and the use of commas.
An important concept to consider when writing is to keep it simple and the message clear. If there are too many commas in your work,
then it is not simple, and probably not clear. Avoid using too many commas.