句子成分辨别

问题描述:

句子成分辨别
Who is it?主语是什么?我们老师说主语是it
而Which is the most important invention?的主语却是which
为什么同是特殊疑问句而一个做主语另外一个是表语?
原题:There's someone knocking at the door.Do you know (who it is)?
Which do you think (is the most important invention)?
括号中是答案

Who is it?翻译 是谁呢?中文很明显感觉得到 “谁”是最重要的,其他两个字都在强调“谁”,是核心,是主语.
Which is the most important invention? 翻译哪一个是呢?“哪一个”是被强调的,“最重要的发明”谁的是“哪一个”,它是核心所以是主语.
这只是便于理解,如果句子更难,这个方法就不太可靠了、