it's important to
后跟做什么=do sth.,表示去做什么很重要
it's important for
后跟什么=sth.,表示對(duì)什么很重要
例：
it's important to ask this question
問這個(gè)問題很重要
it's important for you
這對(duì)你很重要
最后,以上詞組可以合起來用
it's important for sb.to do sth.
例：
it's important for you to ask this question
問這個(gè)問題對(duì)你很重要