there's no auxiliary verbs in chinese, and you needn't change the sentences' structure when you ues them. just add it where it's needed. can, want are used as general verbs; must is used as adverb. well, you needn't remember this, what you should know is their chinese meaning: 1.can- neng(/) ; hui(\ ) eg: *I can speak chinese- wo neng shuo zhong wen & wo hui shuo zhong wen. *Can you speak chinese? - ni neng shuo zhong wen ma? & ni hui shuo zhong wen ma? 2.must- yi ding(/\); bi xu(\-) eg: *you must have been to china.- ni ken ding qu guo zhong guo. (means ni yi ding qu guo zhong guo.) *I must leave now.- wo xian zai bi xu zou le.& wo xian zai bi xu li kai le. 3.want-xiang(v); xiang yao(v\) eg: * I want to eat. - wo xiang chi fan. * what do you want?- ni xiang yao shen me? in fact we learn want as phrase "want to do sth", not just want. sometime chinese would say "i think want a book. -wo xiang yao yi ben shu." the reason for the mistake is that "want" means "xiang" & "xiang yao" in chinese'. can and must is even difficult for those students in china also, so i don't think it's good idea if you learn it by yourself. well, learning is for using. if you don't care about it, just do it! and good luck!

by the way, the four tones are the most important in chinese, for they are used to seperate the different meaning. so only pinyin is not enough, and please pay more attantion to the four tones(-/v\). :)

no auxiliary verb in chinese.only verb. can do...= 能做... must do...= 一定做or一定要做... want to do...= 要做... Chinese/English 名词 n. 动词 v. 形容词 adj. 数词 num. 量词 --- 代词 conj. 副词 adv. 介词 prep. 连词 --- 助词 --- 叹词 --- 拟声词 --- --- art. i hope no mistake in my answer

chinese and english are two completely different languages , so just foget your english grammar, and try to say with chinese thinking, anyway the grammar is not important, the aim is to communicate with chinese people:D can: 能，neng must: 必须，bi xu want: 想要，xiang yao

for example： 能（能够），是，可以，想 etc (they are auxiliary verbs in chinese). Sentence: 他能用流利的英语跟外国朋友交流．englih meaning: He can conmunicate with foreingners in english fluently. this answer maybe is not so good,but hope can help you!