1) wanna = want to = 想要，想做
i wanna go on vacation!
i don't wanna study!
you wanna call me back later?
2) gunna / gonna = going to = 会做
what's gunna happen!?
you're gunna freeze to death if you don't put a hat on!
are you gunna go to melissa's party?
3) coulda = could have = 会有
i coulda, but i didn't。
i thought i coulda gone to the concert. but i had to stay home and study。
don't worry about what coulda been! focus on the future!
4) woulda ＝ would have ＝ 将会
i woulda, but i didn't。
i woulda said yes to going on a date with bob, but my parents woulda killed me! they think i need to focus on my studies。
5) shoulda ＝ should have = 应会，该有
i shoulda, but i didn't。
i shoulda said "yes!" i wanna go on a date with bob!