Commas is a punctuation mark(,). There are five main rules about commas; Rule 1: Commas are used to separate words or phases. Rule 2: Can be used when and can be and also to separate two adjectives. Rule 3: Commas are used when a "ly" adjective is used along with others. Rule 4: Place commas to separate the year from the day of the month. Rule 5: When addressing someone directly use commas before and surrounding their name.