Tú me quieres dejar, y yo no quiero sufrir
You want to leave me, and I don't want to suffer
Caption 8, Javier García - EPKPlay Caption
One of the most interesting, and yet also most common, verbs we find in Spanish is dejar. In caption 8 of his EPK (which, by the way, is entertainment industry talk for "Electronic Press Kit"), Javi sings Tú me quieres dejar... and the meaning is "You want to leave me..." However, twelve captions later we find the imperative (command) form of the same verb being sung to a different tune...
Deja de correr, tranquila
Stop running, take it easy
Caption 20, Javier García - EPKPlay Caption
Here, Javi is not telling us to "leave" running but rather the same verb now means "to stop" ("Stop running, take it easy"). The construction dejar de + infinitivo gives us the equivalent in English of "stop" + gerund (the "-ing" verb form).
Deja de mirarme así.
Stop looking at me like that.
Deja de llorar.
Esta rumba, yo te digo, que te deja por el suelo
This rumba, I'm telling you, leaves you on the floor
Captions 1-2, Javier García - La RumbaPlay Caption
Very similar to a use of "leave" in English, dejar can be used to explain how something effects you. In this case, the rumba is so great and so tiring, it "leaves you on the floor." In a similar vein, you may hear people talking about how an emotional event affected them: La película me dejó sin palabras, or "the movie left me speechless."
La clase de gimnasia me dejó cansadísima.
Gym class left me very tired.
If you keep your ears open, you will also hear dejar used for giving up something, such as...
Voy a dejar francés.
I'm going to quit French.