谁帮我详细讲讲英语中的定语从句

定语从句
Eg:1.He is such a man who never tells a lie.
2. He is the model worker whom/who we should learn from.
3. A dictionary is a book which often helps us to know the meanings of the words.
4. This is the film which I like best.
5. The boy whose father is a professor is one of my best friends.
6. The house whose roof was blown away by the storm will be rebuilt soon.
关系代词which和that的区别：A.关系代词必须用
A.关系代词必须用that的情形：
1、当先行词被形容词的最高级所修饰
This is the best film that I have ever seen.
2、当先行词被序数词修饰
The first car that arrived at the destination was driven by John.
3、当先行词被the only, the very等修饰
This is the only ticket that I got yesterday.
This is the very book that I’m looking for.
4、当先行词为不定代词时或被不定代词修饰时
Is there anything that I can do for you?
All that you have to do is to press the button.
There is no time that we can waste.
5、当先行词既指人又指物时
The car and its driver that knocked