to主系表结构很完整，不是it's important for sb. to do 的结构，to sb.的用法如下：(表示对象)对, 对于, 对…来说 What will Doris say to it?对此事多丽丝将怎么说呢?(表示比较)比, 相对于 The men are noodles to her.与她相比, 这些男人都是笨蛋。
选tobe important to sb.意思是sth.对sb.而言很重要例：Money is important to me. 对我来说钱很重要。be important for sb.（to do sth.）强调做某事对某人的重要性。 例：It is important for you to get there early.
