Clauses

从句是句子的组成部分。英语中有两种从句：独立从句和从属从句。

独立从句包含一个主语和一个动词，所以是完整的句子。独立从句的另一个说法是主从句。

We left the house at 5 a.m.

Hamed eats an apple every day.

Let's go!

从属从句不是完整的句子，需要一个独立的从句才能有意义。如果你从句子中把从属从句去掉，说话者想要传达的信息就没法传递出来。

The car, which was brand new, needed a new wing mirror.

You went with her to the dentist, didn't you?

If you leave now, you'll miss the main event.

关系从句是修饰名词的从属从句。这些从句以关系代词 "who"、 "whose"、"which"、 "where"、"when" 或 "that"开头。

The car that I drove here in is actually my mother's.

His friend, who was wearing a bright red coat, only stayed for half an hour.

Gerald’s new job, which is at LingQ, has made him very happy.

限制性还是非限制性？

关系从句可以是限制性的，也可以是非限制性的。

限制性从句对句子来说是必不可少的。它们会修改名词或名词短语，如果去掉它们，这个句子就没有意义了，或者说话者试图传达的信息就会丢失。

示例:

The muffins that I baked are all low sugar.

The hotel where Angela works will close down in a month.

The person who made us all late should have to clean the bus.

非限制性从句对句子来说是可有可无的，它们提供了额外的信息。如果去掉非限制性从句，这个句子仍然有意义，说话者的信息也可以得到充分表达。

The little girl, who was carrying a yellow backpack, was waiting a long time for her dad.

The old church, which has needed a new roof for years, is very cold in the winter.

Fion Jones, who lives down the road, is going to walk the dog tomorrow morning.