yours

We don’t traditionally think of yours as having synonyms, but there are several situations in which it can replace—or be replaced with—another term.

your

Sometimes you can reword what you’re saying to use your instead of yours. For example, instead of saying I think this seat is yours, you could say I think this is your seat.

your own

The phrase your own is sometimes used as another way of saying yours. Instead of saying Please use yours, you could say Please use your own. 

urs

The form urs is sometimes used as a substitute for yours in very informal communications, such as text messages or online posts, as in i have mine but where’s urs?

Strictly speaking, yours doesn’t have a definitive antonym in the same sense that short is the antonym of long. Of course, possession and association are often distinguished by using contrasting possessives, such as in statements like This responsibility is yours—it’s not mine. In this sense, all of the other possessive words could be considered the opposite of yours, including mine, hers, his, and theirs.

On the other hand, one person’s possession of something does not mean that someone else can’t possess it as well. This is indicated in a lot of popular expressions, such as what’s mine is yours.

Yours is a pronoun. It’s a form of the possessive case of the personal pronoun you that’s used as a predicate adjective (a type of adjective that modifies or describes the subject of a sentence or clause and is linked to the subject by a linking verb, such as a form of the verb be), as in That pencil is yours. It can also be used as a pronoun that functions as the subject, as in Yours is the red one. 

Like the similar possessive words mine, hers, theirs, and ours, yours stands alone and typically never accompanies another noun as a modifier.

In contrast, the word his can be used as both a possessive pronoun (as in That jacket is his) or a possessive adjective (as in That is his jacket).

Yours is used along with second person pronouns (like you and yourself), which are used to address the person being spoken to or reading. In contrast, first person pronouns (like I, me, we, and us) are used to refer to the speaker or writer themselves. Their possessive forms include my, mine, our, and ours. Third person pronouns (like he, she, they, him, her, and them) refer to anyone other than the person doing the addressing or the ones being addressed. Third person possessive forms include his, her, hers, their, and theirs.