非限制性定语从句中的关系代词which和as用法辨析

邵玉金

请看下面两道题：

① He has won the game， was expected.

② He has won the game， was unexpected.

A. that B. which C. it D. as

以上两题选项中均含有关系代词which和as，该选哪一个呢？现就以下几个方面来谈一谈它们的区别（本文所谈的which和as是指引导非限制性定语从句中的关系代词which和as）。

一、位置关系：关系代词which不能放在句首；关系代词as 既可以放在句首也可以放在句末，甚至还可以放在句中。

1. As is known to all， he studies very hard.（不可用which）

2. New concept English is intended for foreign students， which is known to all of us.（which不可放在句首，这里也可以用as）

3. He， as you know， is clever.

二、内涵关系：as有“正如”、“就像”之意，即主从句意义一致；which 则没有此意。

He is a foreigner from North America， as I know from his accent. （as表示“正如”之意）

Tom is so busy that he has to work at weekends， which he doesnt like.

三、先后关系：as引导的多为经常性行为，或先于主句发生的动作；which引导的多表示发生在主句之后的行为。