8.1 stop doing/to do

　　stop to do　停止，中斷做某事后去做另一件事，stop doing　停止做某事。例如：

　　They stop to smoke a cigarette.　 他們停下來，抽了根煙。

　　I must stop smoking.　　　　　 我必須戒煙了。

　　典型例題

　　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。由題意可知，她到了山頂，停下來在一個路邊的大石頭上休息。因此，應(yīng)選擇"stop to do sth. 停下來去做另一件事"。而不僅僅是爬山動作的終止，所以stop doing sth.不正確。

　　8.2 forget doing/to do

　　forget to do　忘記要去做某事，forget doing　忘記做過某事。例如：

　　The light in the office is stil on. He forgot to turn it off. 辦公室的燈還在亮著，他忘記關(guān)了。（沒有做關(guān)燈的動作）

　　He forgot turning the light off. 他忘記他已經(jīng)關(guān)了燈了。（已做過關(guān)燈的動作）

　　典型例題

　　---- 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 可知燈亮著，即關(guān)燈的動作沒有發(fā)生，因此用forget to do sth.而forget doing sth表示燈已經(jīng)關(guān)上了，而忘記了這一事實。此處不符合題意。

　　8.3 remember doing/to do

　　remember to do 記得去做某事，remember doing　記得做過某事。例如：

　　Remember to go to the post office after school. 記著放學后去趟郵局。

　　Don't you remember seeing the man before? 你不記得以前見過那個人嗎?

　　8.4 regret doing/to do

　　regret to do　對將要做的事遺憾，regret doing　對做過的事遺憾、后悔。例如：

　　I regret to have to do this, but I have no choice. 我很遺憾必須這樣去做，我實在沒有辦法。

　　I don't regret telling her what I thought.　我不為告訴她我的想法而后悔。

　　典型例題

　　---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. 對已發(fā)生的事感到遺憾。regret to do sth. 對將要做的事感到遺憾。本題為對已說的話感到后悔，因此選D。

　　8.5 cease doing/to do

　　cease to do 長時間，甚至永遠停做某事，cease doing　 短時停止做某事，以后還會接著做。例如：

　　That department has ceased to exist forever. 那個系已不復存在。

　　The girls ceased chatting for a moment when their teacher passed by. 姑娘們在老師走過時，停了會聊天。

　　8.6 try doing/to do

　　try to do　努力，企圖做某事，try doing　試驗，試著做某事。例如：

　　You must try to be more careful. 你可要多加小心。

　　I tried gardening but didn't succeed. 我試著種果木花卉，但未成功。

　　8.7 go on doing/to do

　　go on to do　做了一件事后，接著做另一件事，go on doing　繼續(xù)做原來做的事。例如：

　　After he had finished his maths，he went on to do his physics. 做完數(shù)學后，他接著去做物理。

　　Go on doing the other exercise after you have finished this one. 作完這個練習后，接著做其他的練習

　　8.8 be afraid doing/to do

　　be afraid to do　不敢，膽怯去做某事，是主觀上的原因不去做，意為"怕"，be afraid of doing　擔心出現(xiàn)doing的狀況、結(jié)果。doing 是客觀上造成的，意為"生怕，恐怕"。例如：

　　She was afraid to step further in grass because she was afraid of being bitten by a snake.

　　她生怕被蛇咬著，不敢在草叢中再走一步。

　　She was afraid to wake her husband. 她不敢去叫醒她丈夫。

　　She was afraid of waking her husband. 她生怕吵醒她丈夫。

　　8.9 be interested doing/to do

　　interested to do　對做某事感興趣，想了解某事，interested in doing　 對某種想法感興趣，doing 通常為想法。例如：

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

　　I'm interested in working in Switzerland. Do you have any idea about that?

　　我對在瑞士工作感興趣。你想過這事嗎? （一種想法）

　　8.10 mean to doing/to do

　　mean to do　 打算、想，mean doing　意味著。例如：

　　I mean to go, but my father would not allow me to. 我想去，但是我父親不肯讓我去。

　　To raise wage means increasing purchasing power. 增加工資意味著增加購買力。

　　8.11 begin（start） doing/to do

　　begin / start to do sth /begin / start doing sth.

　　1） 談及一項長期活動或開始一種習慣時，使用doing。例如：

　　How old were you when you first started playing the piano? 你幾歲時開始彈鋼琴？

　　2） begin, start用進行時時，后面動詞用不定式to do。例如：

　　I was beginning to get angry。我開始生起氣來。

　　3） 在attempt, intend, begin, start 后接know, understand, realize這類動詞時，常用不定式to do。例如：

　　I begin to understand the truth。我開始明白真相。

　　4） 事物作主語時。例如：

　　The snow began to melt.雪開始融化了

　　8.12 感官動詞 + doing/to do

　　感官動詞 see, watch, observe, notice, look at, hear, listen to, smell, taste, feel + do表示動作的完整性，+doing 表示動作的進行性。例如：

　　I saw him work in the garden yesterday. 昨天我看見他在花園里干活了。（強調(diào)"我看見了"這個事實）

　　I saw him working in the garden yesterday.（強調(diào)"我見他正干活"這個動作）昨天我見他正在花園里干活。

　　典型例題

　　1）They knew her very well. They had seen her ___ up from childhood.

　　A. grow　 B. grew　 C. was growing　 D. to grow

　　答案：A。因題意為，他們看著她長大，因此強調(diào)的是成長的過程，而非正在長的動作，因此用see sb do sth 的句型。

　　2）The missing boy was last seen ___ near the river.

　　A. playing　 B. to be playing　　C. play　　D. to play

　　答案A. 本題強調(diào)其動作，正在河邊玩，應(yīng)此用see sb. doing sth句型。