What is are some example sentences when who or whom are used as pronouns?

The pronouns 'who' and 'whom' are both interrogative pronouns (they introduce a question), and a relative pronoun (they introduce a relative clause). The pronoun 'who' is the subjective form, the pronoun 'whom' is the objective form. Example sentences:

Interrogative: Who is your lab partner?

Relative: The woman who was driving the car was not injured.

Interrogative: To whom shall I give my completed application?

Relative: The customer for whom we made the cakewill pick it up at three.