Apostrophes are used in two situations: to form possessive nouns and to form contractions. Possessive nouns show ownership. For example, look at this sentence: "My brother's favorite food is tacos." In this sentence, "brother's" is possessive; the brother owns (or has) the food. Contractions are single words that use an apostrophe to combine two words. "Can't," "I'll," and "she'd" are all contractions. Read on to find out the rules for forming possessives and contractions.

The correct placement of the apostrophe is the key to forming possessive nouns. To do this, you need to know whether the owner is singular or plural. A singular noun refers to one person, place, or thing. For example, "Sheila," "Rhode Island," and "store" are all singular nouns. A plural nouns refers to more than one person, place, or thing. "Snails," "men," and "books" are some examples of plural nouns.

If the noun is singular, add an apostrophe and an "s" to form the possessive. These additions always come at the end of the word. For example, if you want to talk about the desk that belongs to a teacher, you would write, "the teacher's desk." Or, if you are writing about apples that belong to a farmer, you would say, "the farmer's apples." Note that some names end with "s" but still refer to singular nouns, such as "Chris" or "James." The rule for singular nouns holds, regardless of how the name ends. So, "Jess's pencil" is the proper way to write about the pencil that belongs to Jess.

If the owner is plural, look at the last letter of the word. Does it end in "s"? If so, just add an apostrophe at the end. For example, to talk about a club that belongs to a bunch of boys, you would write, "boys' club." Similarly, "cities' economy" refers to the economy shared by one or more cities.

If a plural noun does not end in an "s," add an apostrophe and an "s" to form the possessive. So, if you're writing a book for children to read, you're creating a "children's book." If in that book, a group of mice share some cheese, you would write, "mice's cheese."

Use an apostrophe to take the place of one or more missing letters in a contraction. For example, "can't" is a combination of the words "can" and "not." The apostrophe takes the place of the "n" and "o" in "not." Keeping this rule in mind can help you avoid misusing contractions. For example, when considering to use the contraction "we're" in a sentence, make sure that "we are" makes sense in its place. If not, you may mean "where" (in reference to place) or "wear" (as in wearing clothes).