1. Pronoun/Antecedent Agreement
Rule # 12

2. Pronoun/Antecedent Agreement
Pronoun – takes the place of a noun and sometimes refers to a noun.
A pronoun should agree in gender, number, and person with its antecedent (the word to which the pronoun refers)
These indefinite pronouns are always singular – anybody, anyone, anything, each, either, everybody, everyone, neither, nobody, no one, nothing, one, somebody, someone, or something
The indefinite pronouns some, any, all, most, more, and none, can be singular or plural, depending on the meaning of the sentence.

3. Usage
Incorrect option: When a student does not want to do their teacher’s homework, the student should still try. Correct option: When a student does not want to do his or her teacher’s homework, the student should still try. Incorrect option: If anyone has an opinion about the book, they should state it. Correct option: If anyone has an opinion about the book, he or she should state it.