be interested doing/to do

　　interested to do　　 对做某事感兴趣，想了解某事。

　　interested in doing　 对某种想法感兴趣，doing 通常为想法。

　　I shall be interested to know what happens. 我很想知道发生了什么事。 (想了解)

　　I'm interested in working in Switzerland. Do you have any idea about that? 我对在瑞士工作感兴趣。你想过这事吗？　 (一种想法)

　　mean to doing/to do

　　mean to do　 打算、想

　　mean doing　意味着

　　I mean to go, but my father would not allow me to. 我想去，但是我父亲不肯让我去。

　　To raise wage means increasing purchasing power. 赠加工资意味着增加购买力。

　　begin(start) doing/to do

　　begin / start to do sth

　　begin / start doing sth。

　　1) 谈及一项长期活动或开始一种习惯时，使用doing。

　　How old were you when you first started playing the piano? 你几岁时开始弹钢琴？

　　2) begin, start用进行时时，后面动词用不定式to do

　　I was beginning to get angry.　我开始生起气来。

　　3) 在attempt, intend, begin, start 后接know, understand, realize这类动词时，常用不定式to do。

　　I begin to understand the truth.　我开始明白真相。