your是第二人称形容词性物主代词,单复数同形,在句中用作定语,也可用作动名词的逻辑主体。

Have you brought your toothbrush with you?你带牙刷来了吗?
Your pants are dirty.你的裤子脏了。
I hope he doesn't mind your saying it.我希望他不介意你说的话。

［词源］＜古英语eower(你的,你们的)