SEMICOLON
Like the colon, the semicolon has one very common use (the first one listed below), but other less obvious ones exist.
SEMICOLON RULES
I. Use a semicolon to join two independent clauses
. The semicolon goes in the same place you would normally put a period to separate two sentences; the only difference is that the semicolon joins the two clauses (or sentences) and forms a compound sentence.
A. You may use a semicolon (instead of a comma+FANBOYS) to separate two or more closely related independent clauses.
— Mariana is not coming for Thanksgiving this year ; she has to work all week.
— Mariana is not coming for Thanksgiving this year, for she has to work all week.
— The crash was unavoidable ; the red Ford was demolished.
— The crash was unavoidable , and the red Ford was demolished.
B. You should use a semicolon (instead of a comma+FANBOYS) to separate independent clauses which are long and complicated or which have internal commas.
— My best friend, Christina Moore, was going on a Christmas ski trip to Aspen, Colorado ; but her brother Rob, who is a graduate student at the University of Hawaii in Honolulu, Hawaii, asked her to visit him instead. (Notice all the internal commas. Simply adding a comma before the FANBOYS would just blend in with all the other commas, but using a semicolon before the FANBOYS makes it clear that this is a compound sentence.)
II. Use a semicolon to separate the items of a list or series if any of the items in the series already contains commas.
—The plants growing in my backyard include an avocado, a tree; tomatoes, vines; and chrysanthemums, flowers. (The semicolons tell the reader that an avocado is a tree, tomatoes are vines, and chrysanthemums are flowers. Without the semicolons, a reader might think these are six different things, rather than just three.)
— Last year, representatives from Atlanta, Georgia; Birmingham, Alabama; Jackson, Mississippi; and Chattanooga, Tennessee, attended the national mayors' conference on inner-city problems. (The semicolon after each state tells the reader that Atlanta is in Georgia, Birmingham is in Alabama, and so on.)
PRACTICE
To try a practice, click one of the links below.