Punctuation is used to create sense, clarity and stress in sentences.
You use punctuation marks to structure and organise your writing.
The most common of these are:
- . the period (or full stop in British English)
- , the comma,
- ! the exclamation mark
- ? the question mark
- : the colon
- ; and semi-colon
- “ the quote
- ‘ the apostrophe
- – the hyphen and dash
- ( parentheses and brackets.
Capital letters are also used to help us organise meaning and to structure the sense of our writing.
Check here for more info: http://www.english4today.com/englishgrammar/punctuation/index.cfm