Commas
The neat little comma indicates nothing more confusing than a pause. Despite its modest nature, however, it is woefully misused. This is not necessary if you remember a few simple principles.
the shopping list comma
Commas are used to separate the items in a list in place of 'and'.
Maisie went shopping for bread, milk, butter and eggs.
It is particularly important in some sentences.
John's hobbies were cooking his family his dog and his garden.
In American English and less commonly in British English, a comma is put before the final and. This is known as the Oxford or serial comma.
John liked red, blue, green, and black cars.
Along with many writers of British English, I find this unnecessary and only use it in instances that would otherwise be confusing.
Peter's favourite sandwiches were ham and tomato, cheese and pickle, and peanut butter and jam.
Memory jogger: a comma breaks up a list
the conversational comma
In direct speech, when you are writing exactly what a person said, you need a comma before the quotation mark, whether the speech follows or precedes the text.
As John sat down at the breakfast table, he said to his wife, ‘What a lovely morning.’
‘It certainly is,’ she responded.
The rule is exactly the same if the direct speech is interrupted: the commas go before the punctuation mark.
‘It rained all day yesterday,’ continued John, ‘and I thought it would be raining this morning.’
Memory jogger: a comma introduces speech
subordinate clauses
A subordinate clause (and my all-time favourite cracker joke: what do you call Santa's elves?) is a part of a sentence that supports the main clause; it adds something to the sentence.
If the clause is additional to, but not essential to, the meaning of the sentence, then it is separated by a comma if it is at the beginning or end of the sentence.
Having eaten his breakfast, John set off for work.
He set off at a brisk pace, as he was a little late.
If it is in the middle of the sentence, it is surrounded by two commas.
John was half way to the station, making good time, when he realised he had forgotten his ticket.
In all these examples, you could put brackets around the clause (instead of commas) and take it out without creating nonsense.
John set off for work. He set off at a brisk pace. John was half way to the station when he realised he had forgotten his ticket.
On the other hand, if the clause is essential to the meaning of the sentence, then it does not need commas.
He had no choice but to run home. He knew that travellers who have no ticket cannot board the train.
Here the subordinate clause – ‘who have no ticket’ – cannot be removed without leaving something that makes no sense.
He knew that travellers cannot board the train.
Memory jogger: if you need the words, you don't need the commas
However ...
Remember: if the clause is essential, the comma is not.
Meanwhile, his wife, Mary, put on her coat and left the house. She saw John’s ticket on the table by the door as she left which, naturally enough, reminded her to check she had her own ticket.
‘However’ takes a comma if it falls into this category.
However, she then remembered that she was taking the bus. She put her ticket in her bag, however, just in case.
If however means ‘whichever way’, then it is essential and does not take a comma.
