English grammar

PUNCTUATION RULES
PERIOD
Use a period to end a complete sentence. A sentence is a group of words containing a subject and predicate. In British English a period is called a 'full stop'.Examples:
He went to Detroit last week.
They are going to visit.

COMMA
There are a number of different uses for commas in English. Commas are used to:
o Separate a list of items. This is one of themost common uses of a comma. Notice that a comma is included before the conjunction 'and' which comes before the final element of a list.

Examples:
I like reading, listening to music, taking longwalks, and visiting with my friends.
They would like books, magazines, DVDs, video cassettes, and other learning materials for their library.

o Separate phrases (clauses). This is especiallytrue after a beginning dependent clause or a long prepositional phrase.

Examples:
In order to qualify for your certificate, you will need to take the TOEFL exam.
Although he wanted to come, hewasn't able to attend the course.

o Separate two independent clauses that are connected by a conjunction such as 'but'.

Examples:
They wanted to purchase a new car, but their financialsituation would not allow it.
I'd really enjoy seeing a film this evening, and I'd like to go out for a drink.

o Introduce a direct quote (as opposed to indirect speech i.e. He said he wanted tocome ...).

Examples:
The boy said, "My father is often away during the week on business trips."
His doctor replied, "If you don't stop smoking, you run the risk of a heart attack."

o Separateappositives (a noun, or noun phrase) or non-defining relative clauses.

Examples:
Bill Gates, the richest man in the world, comes from Seattle.
My only sister, who is a fantastic tennis player, isin great shape.

QUESTION MARK
The question mark is used at the end of a question.

Examples:
Where do you live? How long have they been studying?

EXCLAMATION POINT
The exclamation...