HOW是对方式状语提问;WHAT是对表示事物的主语,宾语,表语等提问.
I don't know what to do.(用what是因为不定式to do后缺宾语),I don't know how to do it.( 用how是因为不定式to do后有宾语it,我们也可以用when,where,why 等表示状语的疑问词)
HOW是对方式状语提问;WHAT是对表示事物的主语,宾语,表语等提问.
I don't know what to do.(用what是因为不定式to do后缺宾语),I don't know how to do it.( 用how是因为不定式to do后有宾语it,我们也可以用when,where,why 等表示状语的疑问词)