What part of speech is asleep in you fell asleep?

In the sentence "you fell asleep", the word "asleep" is an adjective.

Here's why:

* It modifies the noun "you": It describes the state of the person ("you") after falling asleep.

* It doesn't act as a verb: "Fell" is the verb in this sentence, while "asleep" describes the result of the action.

Think of it like this: "You" are "asleep," just like you could be "tired" or "awake."