非限制性定语从句有几种

非限制性定语从句有两种：一类是引导词为“which”的从句，另一类是引导词为“who”、“whom”、“whose”的从句。这两种从句在句中起补充说明的作用，但并不影响主句的意义。

非限制性定语从句在英语中用于提供额外信息，但不对先行词产生限制作用。以下是九种常见的非限制性定语从句类型及其用法示例。

1. who 引导的非限制性定语从句

关系代词 "who" 用于指代人，并在从句中充当动词宾语或介词宾语。

• Our guide, who was a French Canadian, was an excellent cook.
• Then he met Mary, who invited him to a party.
• My gardener, who is very pessimistic, says that there will be no apples this year.

2. whom 引导的非限制性定语从句

关系代词 "whom" 同样用于指代人，在从句中作动词宾语或介词宾语。

• Peter, whom you met in London, is now back in Paris.
• Mr Smith, from whom I have learned a lot, is a famous scientist.

3. whose 引导的非限制性定语从句

关系代词 "whose" 作为所有格形式，用于指代人、动物或无生命的事物，并在从句中作定语。

• The boy, whose father is an engineer, studies very hard.
• Above the trees are the mountains whose magnificence the river faithfully reflects on the surface.
• The play, whose style is rigidly formal, is typical of the period.

4. which 引导的非限制性定语从句

关系代词 "which" 可以指代主句中的名词、形容词、短语、从句或整个主句，并在从句中作主语、宾语、介词宾语或表语。

• These apple trees, which I planted three years ago, have not borne any fruit.
• She is an artist, which I am not.
• Water, which is a clear liquid, has many uses.
• The two policemen were completely trusted, which in fact they were.
• She was very patient towards the children, which her husband seldom was.
• She is always careless, which we should not be.
• He said that he had never seen her before, which was not true.
• In the presence of so many people he was little tense, which was understandable.
• He may have acute appendicitis, in which case he will have to be operated on.
• When deeply absorbed in work, which he often was, he would forget all about eating and sleeping.

5. when 引导的非限制性定语从句

关系副词 "when" 在从句中作时间状语，指代主句中表示时间的词语。

• He will put off the picnic until May 1st, when he will be free.

6. where 引导的非限制性定语从句

关系副词 "where" 在从句中作地点状语，指代主句中表示地点的词语。

• They went to London, where they lived for six months.
• They reached there yesterday, where a negotiation of sale will be held.

7. as 引导的非限制性定语从句

"as" 引出非限定性定语从句时，代替整个主句，对其进行说明。

• As it known to the United States, Mark Twain is a great American writer.
• He forgot to bring his pen with him, as was often the case.
• He is absorbed in work, as he often was.
• Boy as he was,
  关键字： 限制性 定语