关于英语疑问代词 疑问副词+不定式的问题

首先我告诉你,这不是一个从句.句子的主语是what to do这是一个疑问词加不定式结构,不是句子,所以整个句子也不算从句.What I should do is a problem.这才是个主语从句.
参看：
英语有个很有用的结构,就是：疑问词+不定式动词.
疑问词是疑问代词“who,whom,what,which,whose”和疑问副词“when,where,how,why ”.此外,连接词“whether”也适用.
“疑问词+不定式动词”结构有何功用呢?其主要功用有下列五种：
⑴当主语,如：
● When to hold the meeting has not yet been decided.
● Where to live is a problem.
● How to cope with the rising cost of living becomes a daily discussion topic.
⑵当宾语,如：
● We must know what to say at a meeting.
● He could not tell whom to trust.
● Do you know how to play bridge?
⑶当补足语,如：
● The problem is where to find the financial aid.
● The question is who to elect.
⑷当名词同位语,如：
● Tom had no idea which book to read first.
● Do you have a rough impression how to do it?
⑸当宾语补足语,如：
● Jim is not sure whose to choose.
● Mary and John are not certain whether to get married or not

what to do是句子的主语，这个主语是不定式
what是 to do的宾语，本来应该是to do what
但这里what是引导词或者说是疑问代词 所以放句首

what to do是句子的主语，这个主语是不定式
what是 to do的宾语，本来应该是to do what
但这里what是引导词或者说是疑问代词 所以放句首
同意这个说法！简单明了