一、what to do的意思及用法
what to do意为做什么、怎么办，问的是动作的对象，而what是代词在句中中做宾语，所以what to do中不需要再加宾语。例句有：
1、I don't quite know what to do next.
我不太清楚下一步该怎么办。
2、He was considering what to do next.
他在考虑下一步怎么办。
3、I just don't know what to do for the best.
我就是弄不清做什么才好。
4、She never had the least idea what to do about it.
这事怎么办，她一点主意都没有。
5、I don't know what to do with all the food that's left over.
我不知道怎样处理所有这些剩饭剩菜。
二、how to do的意思及用法
how to do意为怎么做，问的是动作的方式，而how是副词，因此how to do需要加宾语。例句有：
1、I taught my daughter how to do pision at the age of six.
女儿6岁时我就教她如何做除法了。
2、Ask me if you're not sure how to do it.
你要是拿不准怎么干，就问我。
3、It's not up to you to tell me how to do my job.
还轮不到你来告诉我怎么做我的事。
4、She did not take the judge's advice about how to do her job
她没有听取评审的工作建议。
5、Give us some pointers on how to do the job.
这工作怎么搞法，你给我们出一些点子。
