Pronouns are short words used in place of a noun. Personal pronouns, which refer to people, are often used to express various levels of politeness towards the person being referred to. Even English used to have this distinction, referred to as “T-V” based on the much-studied French pronouns tu and vous. 

Personal pronouns usually come in singular and plural versions, even though “standard” English seems to be lacking one for the second-person plural. Plural and singular pronouns can also be used to mean more than belonging to a group: in English, the royal “we” or the “majestic plural” is used by a single person to refer to themselves. They can also be distinguished in other ways, like gender, although some would argue such pronoun division is becoming obsolete. Some languages also have different plural pronouns used when differentiating between inclusive and exclusive groups: “us, but not them” and “us, and them."