An apostrophe (‘) is commonly used to form the possessive of nouns and some pronouns, and to mark the omission of letters in a contraction.

Use an apostrophe when the meaning of “it’s” is “it is.” (Using it’s when the word does not mean “it is” is one of the most common mistakes in the English language!)

Note that it’s never correct to use an apostrophe in a possessive version of its. This means that anytime you see “ its' ” with an apostrophe after the s, it is incorrect.