What are the rules for using relative clauses?

Relative clauses are a type of dependent clause that provide additional information about a noun or pronoun in a sentence. They are introduced by relative pronouns (such as who, whom, whose, which, and that) or relative adverbs (such as when, where, and why). The rules for using relative clauses are as follows:

1. Relative pronouns: The choice of relative pronoun depends on the noun or pronoun being referred to and the role it plays in the relative clause. For people, we use "who" for subjects, "whom" for objects, and "whose" to show possession. For things, we use "which" for both subjects and objects, and "whose" to show possession. "That" can be used for both people and things, but it is more commonly used for things.

2. Placement of relative clauses: Relative clauses can be placed immediately after the noun they modify or at the end of the sentence. When the relative clause is essential to the meaning of the sentence, it is not set off by commas and is placed immediately after the noun. When the relative clause provides additional, non-essential information, it is set off by commas and is placed at the end of the sentence.

3. Omission of relative pronouns: In some cases, the relative pronoun can be omitted if it is the object of the relative clause and the verb in the relative clause is not a linking verb. This is known as a reduced relative clause.

4. Agreement: The verb in the relative clause should agree in number and person with the noun or pronoun it refers to. For example, if the noun is singular, the verb in the relative clause should be singular as well.

5. Ambiguity: Care should be taken to ensure that the relative clause is clear and does not create any ambiguity. This can be achieved by placing the relative clause close to the noun it modifies and by using appropriate relative pronouns.

By following these rules, one can effectively use relative clauses to provide additional information and enhance the clarity and coherence of their writing.