疑问词加不定式I dont't know how to do it.一定要加it吗?为什么?这句话是宾语从句吗?

疑问词加不定式I dont't know how to do it.一定要加it吗?为什么?这句话是宾语从句吗? 疑问词加不定式做介词宾语时的介词是什么例如：I don`t know how to improve my English.中的介词是什么呢? 为啥要用不定式加疑问词我英语烂,麻烦各位说明白点例I do not know what to do ,为啥非要用to do I dont't know what can't be came ture! i dont know f why?I dont know! i dont know her “i dont know chinese ” 什么叫动词跟疑问词加不定式? 特殊疑问词加不定式(请多举例) 疑问词后面为什么能加不定式? 疑问词加不定式做什么语? 疑问词后面一定要加不定式吗 疑问词加不定式能否构成从句,.例如：I wanted to know how to make sandwiches.是否是宾语从句,我知道它能与I wanted to know how you make sandwiches互换,但前者是否是简单句仍有争议,还有,如果疑问词加不定 Simon doesn't know what to do.将句子转换成wh-疑问词+动词不定式的简单句 “I dont know !”是什么意思啊? i dont want to know 英语 疑问词加不定式There are so many kinds of tape-recorders on sale that I can't make up my mind which to buywhich to buy做从句的什么成分,定语还是宾语补足?为什么?