It's difficult to do sth 其中it 是形式主语,不定式是真正的主语含义为“去做某事难”
It's difficult for sb to do sth 其中for sb 是 to do 的逻辑主语含义为对某人来说做某事难
我们也会看到这样的句子:It's difficult to sb. 这里it 是代词,代具体的事情。是 to 还是for 看具体情况啊
it's difficult to do sth. 做某事很难 (即后面加事)
it's difficult for sb. 对某人很难(即后面加人)
to后接动词, for后接名词。在意思上也有区别 :to不翻译,for则有“相对于”的意思
楼上的都说了~
就举个例子给你好了~
It's difficult to study Math.
学习数学很困难。
It's difiicult for me to study Math.
对我来说,学习数学很困难。
因为我数学很烂~哈哈~