主语从句中时态的问题

主语从句中 时态问题 比如

1、It seems that he was right.

1/这对吗？主句是一般时，主语从句可以是一般过去时吗？

2/that he was right. 可否看成是表语从句？

2、 It has turned out that he was right. 对

It has turned out that he is right. 错

第一句对，第二句错，是吗？



It seems that he was right.正确无误。其表达的意义为：目前看来他当时是对的。

至于这个that从句是什么从句，语法家也有争论。

第一种看法觉得that从句是表语从句，但这没办法讲解it指什么。

第二种看法觉得that是主语从句，it是形式主语。但却很难讲解that从句为何不可以谓语句首，如：That he was right seems.

假如给seems后加个形容词，如obvious，

It seems obvious that he was rigght. 则that从句无疑为主语从句。

从《剑桥语法》提高主语结构的转换来看，好像根据主语从句讲解更为合理。试比较：

It is believed that he was right. （it为形式主语，that引导主语从句）

He is believed to have been right. （提高主语结构）

It seems that he was right. it为形式主语，that引导主语从句

He seems to have been right. (提高主语结构）

It has turned out that he was right. 对

It has turned out that he is right. 对

从句用过去时，是由于be right与目前无关。用目前时是由于be right在目前依旧有效。