1. stop doing/to do
stop to do 停止，中断做某事后去做另一件事。
stop doing 停止做某事。
They stop to smoke a cigarette. 他们停下来，抽了根烟。
I must stop smoking.. 我必须戒烟了。典型例题
She reached the top of the hill and stopped ___ on a big rock by the side of the path.
A. to have rested B. resting C. to rest D. rest
答案：C 。由题意可知，她到了山顶，停下来在一个路边的大石头上休息。因此，应选择 "stop to do sth . 停下来去做另一件事" 。而不仅仅是爬山动作的终止，所以 stop doing sth . 不正确。
2. forget doing/to do
forget to do 忘记要去做某事。 ( 未做 )
forget doing 忘记做过某事。 ( 已做 )
The light in the office is stil on. He forgot to turn it off.
办公室的灯还在亮着，它忘记关了。 ( 没有做关灯的动作 )
He forgot turning the light off.
他忘记他已经关了灯了。 ( 已做过关灯的动作 )
Don't forget to come tomorrow.
别忘了明天来。 (to come 动作未做 )
---- The light in the office is still on.
---- Oh，I forgot___.
A. turning it off B. turn it off C. to turn it off D. having turned it off
答案：C 。由 the light is still on 可知灯亮着，即关灯的动作没有发生，因此用 forget to do sth.
而 forget doing sth 表示灯已经关上了，而自己忘记了这一事实。此处不符合题意。
3. remember doing/to do
remember to do 记得去做某事 ( 未做 )
remember doing 记得做过某事 ( 已做 )
Remember to go to the post office after school.
Don't you remember seeing the man before?
4. regret doing/to do
regret to do 对要做的事遗憾。( 未做 )
regret doing 对做过的事遗憾、后悔。( 已做 )
I regret to have to do this, but I have no choice.
I don't regret telling her what I thought.
---You were brave enough to raise objections at the meeting.
---Well, now I regret ___ that.
A. to do B. to be doing C. to have done D. having done
答案：D 。 regret having done sth. 对已发生的事感到遗憾。 regret to do sth. 对将要做的事感到遗憾。本题为对已说的话感到后悔，因此选 D 。
5. cease doing/to do
cease to do 长时间，甚至永远停做某事。
cease doing 短时停止做某事，以后还会接着做。
That department has ceased to exist forever.
The girls ceased chatting for a moment when their teacher passed by.
6. try doing/to do
try to do 努力，企图做某事。
try doing 试验，试着做某事。
You must try to be more careful.
I tried gardening but didn't succeed.
7. go on doing/to do
go on to do 做了一件事后，接着做另一件事。
go on doing 继续做原来做的事。
After he had finished his maths，he went on to do his physics.
Go on doing the other exercise after you have finished this one.
8. be afraid doing/to do
be afraid to do 不敢，胆怯去做某事，是主观上的原因不去做，意为 "怕" 。
be afraid of doing 担心出现 doing 的状况、结果。doing 是客观上造成的，意为 "生怕，恐怕" 。
She was afraid to step further in grass because she was afraid of being bitten by a snake.
She was afraid to wake her husband.
She was afraid of waking her husband.
9. 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 )