意思類似,但是用法不同
it seems that + 從句
as if 不能單獨引導句子,一般跟在另一個句子后面,as if 后可加從句、ing形式、不定式等.如：
It seems that it is going to rain. =It looks as if it is going to rain.
He stood up as if to say something. 他站起來好像要說什么.
He stood there as if saying something. 他站在那兒好像在說什么.
He talked as if he were a teacher . 他說話的樣子好像他是老師似的.（虛擬語氣）
as if后面的句子是否是虛擬語氣要取決于句子的意思.
【英語牛人團】