Punctuation
Rules, rules, rules
Here is where rules are confronted. But it is best not to think of them as rules, but rather as conventions. Punctuation is a sticky area; few are able to get away with creative use. Most professors require that you use standard punctuation in your documents. But is is only because they, like every reader, expects a punctuation mark to do a certain thing (a comma means a pause, for example) and if a comma, let's say, is used instead of a period, let's say, then confusion results.
Comma
Most mistakes are made with comma use. The comma has an important function. It is used to mark a pause in a speech, otherwise a really long line becomes breathless and confusing.
Percy Shelly in a boat made of wood saw the shore for the last time.
Often a comma is substituted for a period which is commonly called a comma splice. A comma usually marks a pause, like that. Or it can separate a subordinate clause, like this one, from the rest of the sentence. Doing the latter requires two.
Semi-colon
A semi-colon separate two sentences that contribute to the same idea. Such as:
Semi-colons are useful with extended ideas; but make sure each side of the mark contains a complete sentence.
Colon
A colon marks the beginning of a list, or can be used in place of the word namely.
There are three ways to win at cards: lie, cheat and steal.
or
I always win at cards when I apply a few principals: {namely} lying, cheating and stealing.
Dash
The dash has few rules, and is consequently one of the handiest and misused marks in the English language. A dash usually is used to imply a break in thought, a shift in the text, or an after-thought. What is important to remember when using a dash it that it is the most visible punctuation mark, and using too much of it makes the text look broken and read choppy.
