1、三者的意思不同gotta = have got to，必须，要，也就是相当于have to；gonna = going to，将要；wanna = want to，想要做某事。
2、用法不同gotta = have got to，必须，要，例如： have got to go now. = I gotta go now. 我现在必须要走了。I gotta leave here tomorrow. 我明天得离开这儿。gonna = going to，将要，它的前面应该还有个be动词，等同于be going to.例如：I am going to play piano now. = I’m gonna play piano now. 我现在要弹钢琴了。We are gonna meet you at the gate of the zoo. 我们将在动物园门口见。wanna = want to，想要做某事这些个片语算是由于长期口语化之下的产物，一般较正式的场合，文件之类的，不会出现的。但是在一般日常生活，已被大家接受，并大量出现在流行文化中，比方是流行歌曲的歌词里面。例如：I want to go swimming. = I wanna go swimming. 我想游泳。I wanna have a big dinner. 我想大餐一顿。
