What is Dash, Parenthesis, Hyphen, Colon, and Semicolon?
Dash (_)
A dash, represented as a long dash, or as two "short dashes" (--), occurs mostly in informal writing. It is used to set off information that interrupts the main sentence. In formal writing, it is best to use commas to set off this type of information.
Example
I believe that my excuse--my broken ankle--is quite plausible, and I don't know why the teacher doesn't believe it.
Be careful not to confuse the dash with the hyphen (see below).
Parentheses ( )
Parentheses ( ) are used to set off additional information that further explains something in the sentence, but is not vital to the understanding of the sentence. In formal writing it is best to use this to refer the reader to a place in the work where further information can be obtained, or to define terms. If the information is important, it should be included in the body of the work itself and not set off by parentheses. Most parenthetical information could be included in a descriptive phrase or clause, which would not require the use of parentheses.
Examples
1. Our teacher (who never believes anything I say) wouldn't accept my excuse for being tardy.
2. Photosynthesis (the process by which plants make food using sunlight energy) is the subject of her experiments.
3. Recent studies show that the author was much less of a recluse than has previously been realized (Myers 32).
Hyphen (-)
A hyphen (-) is sometimes used to join compound words such as "well-liked," "well-known," "first-rate," and "first-class" if the compound words are used as adjectives before the nouns they modify.
Example
This is a four-star restaurant.
Do not use a hypen when the compound adjectives are made up of adverbs with "-ly" endings, even when they precede a noun.
Example
Thank you for this clearly written essay.
Some compound words, like "high school," do not take a hyphen, even when they are placed before nouns. If you are unsure if the hyphen is appropriate, look up the word in the dictionary.
In some texts, a hyphen is used to break a word that comes at the end of a line so that the ending of the word will be at the beginning of the next line. This is a device used by publishers to save paper and to create even margins on pages. Student writers should avoid this use of the hyphen.
Note: The hypen resembles a short dash, but the two are different punctuation marks. Be careful not to confuse them!
Colon (:)
A colon (:) is used to set off the items in a list from the sentence introducing the list.
Example
A well-educated person studies the following: literature, science, mathematics, language, history, and art.
If the list is the direct object or predicate nominative of the sentence, do not use a colon.
Example
A well-educated person studies literature, science, mathematics, language, history, and art.
Semicolon (;)
A semicolon (;) is used to join independent clauses in a compound sentence if the coordinating conjunction is left out.
Example
Literature and history are excellent fields of study; science and math are also valuable.
A semicolon is also used to separate items in a list when the items are long or contain commas within them.
Example
The prevailing attitudes were a disrespect for the abilities of women, most of whom were denied education; a lack of feeling for the needs of children, who were often forced to work in squalid conditions; and a complete disregard for the humanity of minorities, many of whom gave their lives to build the country.