英语就是这样( 104 ) 关系从句 Relative Clause

在关系从句 （Relative Clause）里，that 和 which 是否是没有分别？是不是东西，某件事都一律可以用上that 和 which呢？如以下的例子：

The house which I sold to her was damaged in the flood.

The house that I sold to her was damaged in the flood.

关系从句 ( Relative Clause) 有两种，一种是限制或定义关系从句（restrictive (or defining) relative clauses），另一种是无限制或无定义关系从句（non-restrictive (or non-defining) relative clauses）.

限制或定义关系从句（restrictive (or defining) relative clauses）提供有关句子中名词的重要信息被视为不可删除掉的，用which 就比较适合了。

The house which was built in 1900 was damaged in the flood.

以上，如用that 就不大适合，也不能显出1900的重要性了。

在无限制或无定义关系从句（non-restrictive (or non-defining) relative clauses），来形容名词 的信息是可删除掉的，因为它被视为不重要，多余的。

The book that I bought last night was misplaced.

This pen that cost 20 dollars was bought by my brother.

上面的that I bought last night，that cost 20 dollars 是可删除掉。