Semicolons, Colons, and Dashes
In her sleep, she dreamed about her passion: punctuation.
Use a colon after an independent clause to direct attention to a list, an appositive, or a quotation that concludes a sentence
For her talk to the class, Rebecca planned to use several visual props: the chalkboard, two posters, and a short video.
Use a colon before a list of items, especially after such expressions as as follows and the following.
Although Mom was so surprised that she could hardly speak, she finally said: "Thank you all for coming and making my fortieth birthday so special."
Use a colon before a long, formal statement or quotation.
Davie and many of his friends were late for school: They were on their way when the school bus's transmission seized up, and then they had to wait for another bus to pick them up.
Use a colon between independent clauses when the second clause explains or restates the idea of the first, or between a title and its subtitle.
Now Stephan, you know--and we've been over this before--that your homework is your responsibility.
Use a dash to indicate an abrupt break in thought.
I made this cake for the reason I told you--tomorrow is Katrina's birthday.
Use a dash to mean namely, in other words, that is, and similar expressions that come before an explanation.
The tests in this course--The Perilous Punctuation Plunge, for instance--are meant to amuse sophomores strained by stress.
Use a dash to set off appositives that contain commas.
The Perilous Punctuation Plunge--the nemesis of hundreds of sophomores--was composed anonymously.
Use a dash to set off nonessential phrases for emphasis
To prepare for the meeting, Andy arranged the chairs around the conference table; he laid a fresh notepad, a pencil, and a cup of water at each place; and then he set up a microphone for the speaker, Mr. Foster Kern of the Tennessee Industrial Council.
Use a semicolon (rather than a comma) between independent clauses joined by a conjunction when the clauses contain commas.
Bill had one his heat; he caught his breath and drank some water before the finals.
Use a semicolon between closely related independent clauses if they are not joined by and, but, for, nor, or, so, or yet.
Hannah decided not to braid her hair; instead, she wore a bun.
Use a semicolon between independent clauses joined by a conjunctive adverb or transitional expression which is followed by a comma.