Leave one typed space after a semi-colon. Commas Use a comma before and or in a series of three or more items. Use a comma to set off a nonessential clause, that is, a clause that the sentence can do without. Do not use a comma to set off a clause that cannot stand alone. Leave one typed space after a comma.
Parentheses Use parentheses to set off completely independent parts of a sentence.
Use parentheses to set off references in text. Quotation marks Use double quotation marks to introduce a word or phrase used as slang, or as an invented or coined expression. Use quotation marks only the first time such a phrase is used. Do not use double quotation marks to apologize for using an expression in a sarcastic way, as if it means the opposite of what it does. Place periods and commas within the closing double quotation marks.