oxford_guide_to_english_grammar

7 SPOKEN ENGLISH AND WRITTEN ENGLISH PAGE70
56 Punctuation
1 The sentence
A sentence ends with a full stop, a question mark or an exclamation mark.
Punctuation
Example
STATEMENT Full stop We've got the best bargains.
IMPERATIVE Full stop Send for our brochure today.
QUESTION Question mark Have you booked a holiday?
EXCLAMATION Exclamation mark What a bargain!
NOTE
a If a question has no inversion, then we still use a question mark.
You've booked a holiday?
b A request in the form of a question usually has a question mark.
Can you send me a brochure, please?
c There is a question mark after a question tag.
It's a bargain, isn't it?
2 Punctuation between main clauses
a
b
c
There are a number of ways of punctuating two main clauses.
Full stop between separate sentences
Shakespeare wrote plays. He also acted on the stage.
Semi-colon between separate clauses
Shakespeare wrote plays; he also acted on the stage.
Comma between clauses linked by and, but or so
Shakespeare wrote plays, and he also acted on the stage.
No punctuation when the verb follows and, but or so
Shakespeare wrote plays and acted on the stage.
A full stop or semi-colon shows that there are two separate pieces of information.
A comma or no punctuation shows the meanings as more closely linked.
Clauses linked by and, but or so can be without a comma, especially if they are short.
He wrote plays, and he also acted.
He wrote plays and he also acted.
But if there is no linking word, we must put a full stop or semi-colon.
NOT He wrote plays, he also acted.
We can use a dash between clauses, but it is rather informal.
Shakespeare wrote plays - he also acted on the stage.
We can use either a dash or a colon before a clause which is an explanation.
The theatre was full - there were several school parties there.
The theatre was full: there were several school parties there.