my / your / his / her / its / our / their + [noun]
A possessive adjective goes before a noun. It shows who has the thing or who the person is connected to.
Each one goes with a subject pronoun:
The word doesn't change for the noun after it: my brother, my sisters.
His and her follow the owner, not the thing. If the owner is a man, it's his. If the owner is a woman, it's her.
Its means "belonging to it". It's means it is or it has.
Their, there and they're sound the same, and so do your and you're. The spelling shows the meaning.
With parts of the body and with clothes, use a possessive, not the.