In American movies and music it is very common to hear the words gonna, gotta and wanna. They are short forms of talking about the future (gonna), obligation (gotta) and desires (wanna).

Gonna
Gonna is the abbreviated form of going to and so is used to talk about the future.

Sentence/ question with gonna	Grammatically correct sentence/ question
I'm gonna eat. What you gonna do? Where you gonna go?	I'm going to eat. What are you going to do? Where are you going to go?

See also:
Gotta is the abbreviated form of have got to in the sense of having an obligation.

Sentence with gotta	Grammatically correct sentence
I gotta go. You gotta help me. They gotta stop.	I've got to go. / I have to go. You've got to help me. / You have to help me. They've got to stop. / They have to stop.

See also:
Wanna is the abbreviated form of want to.

Sentence/ question with wanna	Grammatically correct sentence
You wanna go? What you wanna do? I don't wanna stay here.	Do you want to go? What do you want to do? I don't want to stay here.