Apostrophes are used in four ways: to show possession (e.g., dog's dinner) in time expressions (e.g., 2 years' pay) in contractions (e.g., isn't) to show awkward plurals, but only very awkward plural (e.g., i's and a's)

An apostrophe is used to show that certain letters have been omitted from a word (contractions, i.e. she’s, it’s…). The apostrophe symbol can also be used to show the possessive form of a noun (possessive apostrophe, i.e. John’s books,…), in addition to indicating the plural form of lowercase letters.

Apostrophe to show two words have been connected (contraction) We sometimes connect two words to make one shorter word. We use an apostrophe to show that we have left out one or more letters: do not → don’t They don’t like salt in their food. it is → it’s It’s a long way to walk.

A few apostrophe examples below: I am – I’m: “I’m planning to write a book someday.” You are – You’re: “You’re going to have a lot of fun with your new puppy.” She is – She’s: “She’s always on time.” It is – It’s: “I can’t believe it’s snowing again.” Do not – Don’t: “I don’t like anchovies.” He would – He’d: “He’d like to go fishing in Alaska.”