Punctuation marks have a lot of different uses. The period, question mark, and exclamation point are used to end sentences. The comma, semicolon, colon, and dash indicate a pause or break. Parentheses contain words, while hyphens combine them. Apostrophes show the omission of letters, and also show possession.
Ending a sentence
A period (.) ends any sentence that forms a statement. Periods are also used in abbreviations. For example, Mr. is the abbreviation for Mister.
Indicating a pause or break
A comma (,) separates elements in a list (or a series), as in “I like pepperoni, sausage, and bacon on my pizza.” A comma can also separate two complete sentences when combining them with a conjunction. For example: “He went to the gym, and she went to school.”
A semicolon (;) can connect two complete sentences that are closely related. For example: “My brother is sad; he can’t play outside today.”
A colon (:) can introduce an explanation, an example, a quotation, or a series. For example: “I need a few things from the grocery store: bread, milk, and cheese.”
An em dash (—) shows a break in thought, as in “She stayed home from school—on a Monday, no less—to catch up on sleep.”
Parentheses, (), contain words that further explain a sentence. An example is: “The three boys (all of whom were brothers) played in the park.”
A hyphen (-) combines words or names. For example, the words attorney-at-law, up-to-date, and twenty-five all contain hyphens. Olivia Newton-John is a name that contains a hyphen.
Showing omission or possession
An apostrophe (‘) shows where letters have been omitted from a word. In can’t (a contraction of cannot) the apostrophe shows where the letters N and O were omitted.
An apostrophe can also show that a word is possessive. Here’s an example from Gone With the Wind: “Scarlett felt it was just Melanie‘s way of parading her conquest and getting credit for being sweet at the same time.” Here, the apostrophe shows that the way belongs to Melanie.