如何理解it seem like [as if]是什么从句

问题描述

词典上对于 it seem like [as if]，并没有给出其词性，应该怎样理解它们？如例句：

1. It seems like their relationship is over. 他们的恋爱似乎完了。

    It seems like years since we last met. 我们似乎好几年不见了

2. It seems as if they are no longger in in love. 他们似乎不再相爱了。

    It seems like as if he has been at the scene of the crime. 看样子他好像曾在犯罪现场。

老师答疑

陈老师：

▲根据对外经济贸易大学出版社出版的《英语动词句型和使用》（汪廷弼、陈苏东），以下各句中的 as if, as though, like 引导的从句是“主语补足语”，也就是通常说的“表语”：
1. It seems (to me) as if it will rain. (我看)好像要下雨。
2. It appears (to me) as if he will win. (据我看，)他好像能赢。
3. It sounds as though there is a k nock at the door. 听起来好像有人在敲门。
4. It doesn’t look as if we shall get there in time. 看来好像我们不能及时到达那里了。
5. You look as if you slept badly. 你看起来好像没有睡好。
6. I felt as if my head we’re splitting. 我觉得我的头仿佛要裂开似的。
7. It looks like his last hour has come. 看起来好像他的末日已经到来了。
▲该书的注释如下：
1. 在本句型中，动词 seem，appear，sound，look，feel 等动词均用作系动词，由连词短语 as if 或 as though 所引导的从句用作主语补足语。
2. 例句1—4：在系动词后可直接插入 to 介词短语。
3. 例句5—6：在以上各例句中，用非人称代词 it 作主语。又在 look 和 feel 用作系动词时，可用人称代词作主语。有些语法书认为 feel 后面，as if 所引导的从句为状语从句。
4. 例句7：在非正式文体中，like 用作连词，代替 as if。

黎老师：

It seems as if they are no longger in in love. 他们似乎不再相爱了。

(其中的 as if they are no longger in in love 是表语从句)