The antecedent of his is driver which is masculine gender, third person, singular. Therefore, choose the same kind of verb and pronoun to agree. Use a masculine pronoun in referring to a singular antecedent unless the antecedent is clearly feminine or neuter. No one in the room was wearing his summer clothes. Every one of the girls was wearing her coat.
Somebody is at the door.
There are four of them. Demonstrative pronouns point out . These are used in questions . There are five of them. There are five of them.