Forms and Functions of Punctuation

Form Symbol Function

period 

.

used to end a sentence (a sentence contains a subject, verb and sometimes object and expresses a complete thought; you can "test" a complete sentence by transforming it into a "yes/no" question (see example)
example: " The United Nations began in 1945." (transformed to a 'yes/no' question from a question: Did the United Nations begin in 1945?)

comma

,


used to clarify or highlight  additional information about a subject;  
example: " The United Nations, which had just 50 member-states when it began, now has many                  more.

semi-colon

 ;


used to separate two complete thoughts that could stand alone as two separate sentences; the semi-colon is used to show the close connection between the two thoughts
example: "All member-states have one vote in the General Assembly; therefore, each has an equal say in this forum regardless of its size."


colon 

:

used to give added information about the subject and follows what could stand alone as a complete sentence
example: "In 1995,  five more countries became United Nations members:

m-dash
 

--

used to highlight information but in a more emphatic way than a comma
example: "There is nothing wrong with the United Nations -- except its governments." (a quote from Lord Caradon, Britain's Delegate to the United Nations, 1964-70)


n-dash
 

 -

used to separate components of compound words
example:"By the United Nations' fiftieth anniversary, the number of member-states had more than tripled."

apostrophe
 

'

used to show possession; placed before after the last letter and before s in the case of singular nouns; placed after the final s in plural nouns
example: A Permanent Representative's appointment is for five years.

question mark

?

used to indicate a question
example: "Did the United Nations begin in 1945?"

quotation marks*

    "   "

used to indicate a direct quote from a person
example: The third Secretary-General, U Thant said, "The Charter of the United Nations is the first, most daring code of behaviour addressed to the most powerful institutions of the planet -- armed nations."
* Note that British and American English can use quotation marks differently; British Enlgish useage puts the periods and commas inside the quotation marks, only when such marks are part of the quote itself, while American English always puts periods and commas inside punctuation marks.