Serial Commas: If you are following CMS usage rules, you will use a serial comma. Ex. The flag is red, white, and blue. (The underlined comma is the serial comma.) And: The rabbit ran under the bench, through the shed, and across the field. If you are following AP rules, you will omit the serial comma.
Colon: The colon introduces a full sentence or a list. For CMS usage, you will not capitalize the first letter of the first word of the sentence that follows the colon unless more than one sentence follows. For AP, you will capitalize the first letter of the first word of a full sentence, even when it stands on its own. For both CMS and AP, if the colon precedes a list, the first word that follows the colon will be lowercase.
Full Sentences: After attending three weeks of camp, Lauren became homesick: She couldn’t sleep, lost her appetite, and cried all the time. It was terrible!
List: Amy chose three paint colors: sky blue, Navajo white, and sunset peach.
Semicolon: The semicolon is used to connect two full sentences that are closely related. It is also used to divide a list that consists of at least one sub-list.
Full Sentences: Samuel loved walking the woods; he would grow up to be a true naturalist.
List: I need to order pearls; charms; and jump rings, findings, and clasps. (The underlined comma is a serial comma. Do not use it if you are following AP style.)
Find out more about punctuation rules in class!