A pronoun is a word that replaces and refers to a noun. It is used in exactly the same way as the noun it replaces.
Bill gave the book to Chris.
He gave the book to me.
There are four types of pronouns: subject pronouns, possessive pronouns, object pronouns, and reflexive pronouns.
Pronouns must always agree with their antecedents. These are the nouns or pronouns they refer to.
Yolanda and Gary both went to work, but she drove a car and he rode a bicycle.
In this example, she refers to Yolanda. Gary is the antecedent of he. Each pronoun has the same characteristics as its antecedent.
Masculine subject (Gary) = Masculine pronoun (he)
Feminine subject (Yolanda) = Feminine pronoun (she)
Singular subject (car) = Singular pronoun (it)
Plural subject (cars) = Plural subject (their)
When a pronoun replaces two or more nouns joined by and, use the plural form of the pronoun
Leon and Bob rode their motorcycles through town.
When the pronoun replaces two nouns joined together by or, nor, either…or, neither…nor, or not only….but also, the pronoun agrees with the last noun in the series.
Not only the dogs but also the cat found its own food
When the pronoun replaces a collective noun, use a singular pronoun if the noun is thought of as a single unit. Use a plural pronoun if the noun is thought of as separate people or things.
The faculty is top-notch; its reputation is unmatched.
The staff are doing their paperwork now.
Because they represent an individual and not a group, use the singular form of the pronoun with the following words:
person neither someone somebody
each no one anyone anybody
either everyone nobody everybody
Each of the teammates got their medal at the closing ceremonies. (Incorrect—the plural pronoun their refers to each, which is singular. Remember singular nouns must match with singular pronouns.)
Each of the teammates got her medal at the closing ceremonies. (Correct!)