各位亲爱的可可网友们，欢迎走进我们今天的《说法话茬》教室。我们今天来分析这个含有定语从句的复合句的错误所在：

The reason of which he lost his wife was lack of medical care.

这句话的意思是：他们的死亡是缺乏医疗造成的。

在这个句子中主句是：the reason was lack of medical care，定语从句是：of which he lost his wife。这个定语从句修饰先行词the reason。

The reason指代原因，在定语从句中做原因状语。我想您很快会想到关系副词why。我们可以用why来引导这个定语从句，即：The reason why he lost his wife。

但是写作者是别出心裁，想用“介词+which”来引导，但是有对这个介词感到迷茫和疑惑。那么究竟这个介词用什么呢？

我现在把the reason放入定语从句中，您来看这个空格处应该用哪个介词：He lost his wife the reason。这个空格处应该用for。这样引导词就是for+which。

因此，我们今天对这个病句的疑问就水落石出了。此外，如果先行词是reason的话，我们还可以用that来代替for which或者是why，而且that，for which或者是why都可以省略。

因此，我们今天的病句可以有四种说法：

1. The reason for which he lost his wife was lack of medical care.

2. The reason why he lost his wife was lack of medical care.

3. The reason that he lost his wife was lack of medical care.

4. The reason he lost his wife was lack of medical care.

记住了，定语从句修饰reason这个表示原因的先行词的时候，可以用for which，why，that来引导，还可以省略这个三个引导词。

您今天有收获吗？如果有收获，就继续锁定我们的《说法话茬》节目，随着我把定语从句扎扎实实地攻破下来。