This guide provides instruction on the basic rules of using a period, comma, colon, semicolon, question mark and exclamation point. Each type of punctuation is followed by an explanation and example sentences for reference purposes.



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:

Separate a list of items. This is one of the most 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 long walks, and visiting with my friends.
They would like books, magazines, DVDs, video cassettes, and other learning materials for their library.

Separate phrases (clauses). This is especially true 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, he wasn't able to attend the course.

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

Examples:

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

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

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."

Separate appositives (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, is in 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 point is used at the end of a sentence to indicate great surprise. It is also used for emphasis when making a point. Be careful not to use an exclamation point too often.

Examples:

That ride was fantastic!
I can't believe he is going to marry her!

Semicolon

There are two uses for a semicolon:

To separate two independent clauses. One or both of the clauses are short and the ideas expressed are usually very similar.

Examples:

He loves studying; He can't get enough of school.
What an incredible situation; it must make you nervous.

To separate groups of words that are themselves separated by commas.

Examples:

I took a holiday and played golf, which I love; read a lot, which I needed to do; and slept late, which I hadn't done for quite a while.
They plan to study German, for their travels; chemistry, for their work; and literature, for their own enjoyment.


Colon

A colon can be used for two purposes:

To provide additional details and explanation.

Examples:

He had many reasons for joining the club: to get in shape, to make new friends, to lose some weight, and to get out of the house.
She gave notice for the following reasons: bad pay, horrible hours, poor relations with colleagues, and her boss.

To introduce a direct quote (a comma can also be used in this situation).

Examples:

He announced to his friends: "I'm getting married!"
She cried out: "I never want to see you again!"

Source : http://esl.about.com/od/englishgrammar/a/a_punctuation.htm

Quotation Marks
(double, single)


We use quotation marks to show (or mark) the beginning and end of a word or phrase that is somehow special or comes from outside the text that we are writing. Quotation marks can be double ("...") or single ('...') - that is really a matter of style (but see below for more about this).

Quotation marks are also called "quotes" or "inverted commas".

1. Use quotation marks around the title or name of a book, film, ship etc:
The second most popular book of all time, "Quotations from the Works of Mao Tse-tung", has sold over 800,000,000 copies and was formerly known as "The Red Book".
'Titanic' is a 1997 movie directed by James Cameron about the sinking of the ship 'Titanic'.

Note that in the above case, we may use "italics" instead of quotation marks. So the above examples would then appear as:
The second most popular book of all time, Quotations from the Works of Mao Tse-tung, has sold over 800,000,000 copies and was formerly known as The Red Book.
Titanic is a 1997 movie directed by James Cameron about the sinking of the ship Titanic.

Obviously, the use of italics is not possible in handwriting or with old-style typewriters.

2. We use quotation marks around a piece of text that we are quoting or citing, usually from another source:
In The Cambridge Encyclopedia of The English Language, David Crystal argues that punctuation "plays a critical role in the modern writing system".

3. Use quotation marks around dialogue or direct speech:
It was a moonlit night. James opened the door and stepped onto the balcony, followed by Mary. They stood in silence for a few moments, looking at the moon. Then Mary turned to him and said: "Do you love me, James?"

4. Use quotation marks around a word or phrase that we see as slang or jargon:
The police were called to a "disturbance" - which in reality was a pretty big fight.

5. Use quotation marks around a word or phrase that we want to make "special" in some way:
Note that sometimes we use "italics" instead of quotation marks.
Double or single quotation marks?



Quotation marks can be double ("-") or single ('-'). If we want to use quotation marks inside quotation marks, then we use single inside double, or double inside single.
He said to her: "I thought 'Titanic' was a good film."
He said to her: 'I thought "Titanic" was a good film.'
Punctuation inside or outside final quotation mark?

If the quoted words end with a full stop, then the full stop goes inside the quotation marks. If the quoted words do not end with a full stop, then the full stop goes outside the quotation marks:
He said: "I love you."
She has read "War and Peace".

Note that in US English, the full stop usually goes inside the quotation marks in all cases:
He said: "I love you."
She has read "War and Peace."

However, US English adopts the British style for question marks and exclamation marks:
He said: "Do you love me?"
Have you read "War and Peace"?
Can you imagine? He has never read "War and Peace"!
How do we indicate quotation marks when speaking?

People may say "quote, unquote" or "open quotes, close quotes" when reading aloud texts containing quotation marks:
On page two it says, quote, Now is the time to invest, unquote.
On page two it says, open quotes, Now is the time to invest, close quotes.

"Quote, unquote" may also be said informally in front of rather than around the quoted words:
The brochure describes the car as, quote, unquote, total luxury.

"Quote, unquote" is sometimes used to mock or show disapproval or disbelief:
Then he arrived with his quote, unquote new girlfriend.

People sometimes say "in quotes" (often putting up their two hands with two fingers extended on each hand, like quotation marks), indicating that the words came from another source, or in a mocking way, or suggesting that they don't quite believe what they have just said:
Then he arrived with his new girlfriend, in quotes.