These are contractions as the other people correctly explained and they are mostly used in spoken English, not when you write :)

Wanna-a short form of "want to" I wanna do it=I want to do it Gonna-a short form of "going to" I'm gonna live my life=I'm going to live my life He's gonna write a book= He's going to write a book Gotta-a short form of "have got to", "has got to" I gotta go now= I have got to go now/I've got to go now You gotta do what you gotta do= you have got to do what you have got to do Be careful with "to", as it must not be omitted after "want (to)/have got (to)/going (to)" and is never used after "wanna/gotta/gonna". Some more for you: Gotcha = got you Gimme = give me

I wanna ask a question means, i want to ask a question. i gotta go means, i got to go or i want to go. i gonna play cricket means i am going to play cricket.

Bill, why not? i think It seems convenient to use this contractions in informal speech. Doesn't it?

you really want to learn street argot?