Comma it is preceded by a semicolon and followed by a comma. Using commas to offset certain adverbs is optional, including "then", "so", "yet", "instead", and "too" (meaning "also"). Commas are often used to enclose parenthetical words and phrases within a sentence (i.e., information that is not essential to the meaning of the sentence). Such phrases are both preceded and followed by a comma, unless that would result in a doubling of punctuation marks or the parenthetical is at the start or end of the sentence. The following are examples of types of parenthetical phrases: A comma is used to separate
Serial comma Serial comma In English language punctuation, a serial comma or series comma (also called an Oxford comma or a Harvard comma) is a comma placed immediately before the coordinating conjunction (usually "and" or "or") in a series of three or more terms. For example, a list of three countries might be punctuated either as "France, Italy,and Spain" (with the serial comma), or as "France, Italyand Spain" (without the serial comma). Opinions among writers and editors differ on whether to use the serial comma, and usage also differs somewhat between regional varieties of English. In American English, not using a serial