Here's why:
* Nominative (Subject): You
* Objective (Object): You
* Possessive (Shows ownership): Your/Yours
You can see that "you" stays the same regardless of its grammatical function in a sentence. This makes it unique among personal pronouns, which often have different forms for nominative, objective, and possessive cases (e.g., "I" vs. "me," "he" vs. "him," "she" vs. "her," etc.).