What are the rules for using indefinite pronouns in a sentence?

The rules for using indefinite pronouns in a sentence are as follows:

1. Agreement with verb: Indefinite pronouns should agree with the verb in terms of number. If the indefinite pronoun is singular, the verb should be singular, and if the indefinite pronoun is plural, the verb should be plural. For example:
- Everyone is responsible for their own actions. (singular)
- Some of the students have completed their assignments. (plural)

2. Agreement with pronouns: Indefinite pronouns should also agree with other pronouns in terms of gender. For example:
- Each student should bring his or her own textbook. (using both masculine and feminine pronouns)
- Everyone should take care of themselves. (using a gender-neutral pronoun)

3. Use of singular pronouns: Some common indefinite pronouns are always singular and should be treated as such. These include anyone, someone, everyone, nobody, somebody, etc. For example:
- Nobody wants to be left behind.
- Someone has left their bag here.

4. Use of plural pronouns: Other indefinite pronouns are always plural and should be treated as such. These include both, few, many, several, etc. For example:
- Many have expressed their concerns about the new policy.
- Both of them are going to the party.

5. Use of singular or plural pronouns: Some indefinite pronouns can be either singular or plural, depending on the context. These include all, any, more, most, none, some, etc. For example:
- All of the cake has been eaten. (singular)
- All of the students have submitted their assignments. (plural)

6. Use of possessive pronouns: Indefinite pronouns can also be used in possessive form. For example:
- Is this book yours? (possessive form of the indefinite pronoun "you")
- I found someone else's wallet.

7. Avoiding double negatives: When using indefinite pronouns, it is important to avoid double negatives. For example:
- I don't have nothing. (incorrect)
- I don't have anything. (correct)

By following these rules, you can effectively use indefinite pronouns in your sentences while maintaining grammatical accuracy.