如:It is not easy to learn English well. 要学好英语不容易。
做某事是...的,比如 It is important to do your job. 做你的工作是很重要的。
it 为形式主语,无实际意义,真正的主语是后面的to do不定式,
这个句型其实是倒过来理解的,用语法来说就是it 是形式主语,后面的to do 是真正的主语。
it is good to learn english .你可以理解成 to learn english is good 。就是:学英语是好的。 it is nice to meet you .
it is important to understand this sentence patten.