ADJECTIVAL CLAUSES

Adjectival clauses begin with relative pronouns. The relative pronouns are used who, whom, whose, which and that.

Who is used when the clause referring to the subject of the sentence is a person. 

Examples:

1. The boy who brought flowers is my brother.

2. The man who came in the afternoon left the parcel for you. 

Whom is used when the clause referring to the object of the sentence is a person.

Examples:

1. The girl whom you were speaking to is my daughter.

2. The girl whom I greeted at the airport is my sister.

Whose is a possessive relative pronoun.

Examples:

1. The girl whose mobile was found in the garden is my cousin.

2. The lady whose mobile was stolen made a report to the police. 

Which is used for living creatures other than human beings or for objects. 

Examples:

1. The purse which you gave me is very nice.

2. The movie which I am going to see has won two awards.

That may be used for all living creatures, including human beings, and for objects. 

Examples:

1. The diary that you gave me is very nice.

2. The bag that you bought yesterday is very beautiful.