What are the rules for using relative pronouns?

The rules for using relative pronouns are as follows:

1. Relative pronouns introduce relative clauses, which provide additional information about a noun or pronoun in the main clause.
2. The most common relative pronouns are "who," "whom," "whose," "which," and "that."
3. "Who" is used to refer to people, while "which" is used for animals and things.
4. "Whom" is used as the object of a verb or preposition, and "whose" shows possession.
5. "That" can be used to refer to both people and things, but it is more commonly used for things.
6. Relative pronouns can be used to replace the subject or object of a sentence, or to show possession.
7. The relative pronoun should agree in number and gender with the noun it refers to.
8. Relative pronouns can be used to combine two sentences into one, creating a more concise and cohesive sentence.
9. The relative pronoun is usually placed immediately after the noun it refers to, but it can also be placed at the beginning or end of a sentence for emphasis.
10. It is important to use the correct relative pronoun based on the context and the noun being referred to.

By following these rules, one can effectively use relative pronouns to provide additional information and create more complex sentences.