非限制性定语从句用as还是which(涉及as he often was)

问题描述

When deeply absorbed in work, _____ he often was, he would forget all about eating or sleeping.

划线处除了填 which 外，可以填 as 吗？

老师答疑

曹老师：

When deeply absorbed in work, _____ he often was, he would forget all about eating or sleeping.

这个句子用which和as都可以，关系代词作从句的表语，先行项为deeply obsorbed in work. 用as则兼有比较意义，意为“正如”；用which则没有这层意思。

陈老师：

When deeply absorbed in work,which he often was, he would forget all about eating or sleeping.

=When deeply absorbed in work,as he often was, he would forget all about eating or sleeping.

=As is the often case, when deeply absorbed in work, he would forget all about eating or sleeping.

as is the often case结构，不可以用关系代词which引导。

参考译文：当他全身心地投入工作中时，他就会废寝忘食，而他经常这样全身心地投入工作。

以上除了用关系代词which引导非限制性定语，还可以用关系代词as引导非限制性定语从句。

备注:如果是 as is often the case 则不可以换为 which.

王老师：

同意English Expert老师的解答。应该用which. 我在网上搜了一下，这个问题在国外英语论坛曾出现过，https://ell.stackexchange.com/questions/31272/which-as-relative-pronoun。