The personal pronoun that is used for singular or plural is you.

The pronoun 'you' can take the place of a singular, plural , or a compound antecedent.

Examples:
Jack, I've made lunch for you. (singular)
Boys, I've made lunch for you. (plural)
Jack and Jill, I've made lunch for you. (plural)

The personal pronoun that refers to the person spoken to is you, the second person.

The pronoun 'you' can take the place of a singular, plural , or a compound antecedent.

Examples:
Jack, I've made lunch for you. (singular)
Boys, I've made lunch for you. (plural)

Jack and Jill, I've made lunch for you. (plural)

The plural pronoun that takes the place of the personal pronoun 'him' as the object of a verb or a preposition is them.

Examples:

Where is dad? I made some lunch for him. (singular)

Where are the boys? I made some lunch for them. (plural)

Where are Jack and Jim? I made some lunch for them. (plural)

The plural form of the personal pronouns 'she' and 'he' is they.

Examples:

She and Jane went to the mall.

They went to the mall.

He and Jack had lunch with us.

They had lunch with us.

Both he and she worked on the project.

They both worked on the project.