why
=for the reason
原因状语
=for which
定语从句
1、定义：一个句子放在定语的位置上，修饰名词或代词；
2、结构：先行词/句子+关系代词/关系副词+从句；
3、三要素
4、特殊用法，只用that，不用which的情况如下
①先行词由all,much,little,few,something,anything,
everything,none,nothing等不定代词修饰或先行词是不定代词本身
All that can be done has been done.
②先行词有the only, the same, the very修饰时。
The articles are the very ones that should be read.
③先行词有形容词最高级和序数词修饰时。
This is the best film that I have ever seen.
④先行词既指人又指物。
We talked about the person and things that we remembered.
⑤句中已经有who或which时，避免重复。
先行词
引导词
句子成分
人
who/that
主
whom/who/that
宾/表
物
that/which
主
that/which
宾/表
人、物
which/whose
=of whom
……人的
=which
……物的
时间名词
when
=介词+which
时间状语
地点名词
where
=介词+which
地点状语
the reason
Who is the man that is making a speech?