Let's break it down:
* Il faut - This is a French expression that translates to "it is necessary" or "one must".
* Que - This is a conjunction that introduces a subordinate clause.
* Je - This is the French pronoun for "I".
* Dors - This is the present tense of the verb "dormir" which means "to sleep".
Therefore, the full phrase "Il faut que je dors" means "It is necessary that I sleep" or simply "I have to sleep".