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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。
