No smoking ( =No smoking is allowed (here) ). （禁止吸烟） 　　
No parking. （禁止停车） 　　
5. 动名词的复合结构作主语 　　
当动名词有自己的逻辑主语时，常可以在前面加上一个名词或代词的所有格，构成动名词的复合结构
(这时，名词或代词的所有格做动名词的逻辑主语)。
动名词的复合结构也可以在句中作主语。例如： 　　 
Their coming to help was a great encouragement to us. 　　

二、动名词作宾语
1.作动词的宾语 　　
某些动词后出现非限定性动词时只能用动名词作宾语，不能用不定式。常见的此类动词有：
admit, appreciate, excuse, stand, advise, allow, permit, avoid,  consider, enjoy, finish     
They went on walking and never stopped talking.他们继续走，说个不停。 
I found it pleasant walking along the seashore.在海滩上走真是乐事。 　　
Mark often attempts to escape being fined whenever he breaks traffic  regulations. 　　
每当马克违反交通规则时，他常常企图逃避罚款的处分。 　　 
2.作介词的宾语 　　
We are thinking of making a new plan for the next term. 我们正考虑为下学期制定新的计划。 　　
Shall we have a rest or get down to doing our work? 我们休息呢还是开始干活？ 　　
3.作形容词的宾语 　　
The music is well worth listening to more than once.  这种曲子很值得多听几遍。 　　
We are busy preparing for the coming sports meet. 我们正为马上到来的运动会忙着做准备。

三、动名词作表语
动名词作表语时句子主语常是表示无生命的事物的名词或what引导的名词性从句。
表语、动名词与主语通常是对等的关系，表示主语的内容，主语、表语可互换位置。 　　
Your task is cleaning the windows.   你的任务就是擦窗户。
(Cleaning the windows is your task.) 　　
What I hate most is being laughed at.  我最痛恨的就是被别人嘲笑。
(Being laughed at is what I hate most.)

四、动名词作定语
动名词作定语往往表示被修饰词的某种用途。如： 　　
a walking stick ＝a stick for walking=a stick which is used for walking 　　
a washing machine=a machine for washing=a machine which is used for washing 　　 
a reading room=a room for reading=a room which is used for reading 　　
a measuring tape=a tape for measuring=a tape which is used for measuring 　　
sleeping pills=pills for sleeping=pills which is used for sleeping

动名词是非限定动词的一种形式，由动词原形+ing构成。它既有动词的特征，又有名词的特征，故称。
动名词也有时态和语态的变化，如表所示（以及物动词write为例），不及物动词没有语态的变化。

时态、语态	主动	被动
一般式	writing	being  written
完成式 having written		having been written

动名词使用注意事项：
1） 动名词做主语时，谓语动词为单数
2） 在动名词和不定式中，作为介词的宾语是动名词
3） 动名词的否定直接在其前加否定词，通过代词的宾格或所有格形式给出逻辑主语
例：I would appreciate you calling back this afternoon.
4） 有些词后只能接动名词
acknowledge;admit; advise;advocate;allow;appreciate; avoid; celebrate; consider; contemplate; defer; delay; deny;
detest; discontinue; dislike; dispute; enjoy; it entails; escape; excuse; explain; fancy; feel like; finish; forgive; can’t help;
hinder; imagine; it involves; keep; it means; mention; mind; miss; it necessitates; pardon; postpone; practice; prevent;
recall; report; resent; resist; risk; suggest; understand...
5） 另外还有一些接-ing形式的常用说法
it’s no good; it’s no/little/hardly any/ use; it’s not/hardly/scarcely use; it’s worthwhile; spend money/time; there’s no;
there’s no point in; there’s nothing worse than; what’s the use/point
6） 有些词后面加不定式和动名词均可
remember,forget,try,stop,go on,continue,stop,regret,cease,mean后面均可用不定式和-ing形式，但意义截然不容。
例：remember to do/doing：
①I remembered to post the letters.（指未来/过去未来将要做的动作）
②I remembered posting/having posted the letters.（我记得做过这个动作）
 forget与remember的用法类似。
 regret的用法：
①I regret to inform you that…（我很遗憾地通知你……）
②I regretted having left the firm after twenty years.（为了“二十年前的离开”而遗憾。）
 try to（努力）与try +–ing（试验）：
①You really must try to overcome your shyness.
②Try practicing five hours a day.

考点名称：过去进行时

• 过去进行时：
  表示在过去某一时刻或某一段时间内进行或发生的动作。其形式为was/were+V-ing。
  常与表示过去的时间状语连用，如：
  last night，last Saturday等；
  或者与when,while,as引导的过去时间状语连用。

• 过去进行时的结构：
  1. 过去进行时由“主语+was/were + 现在分词”构成
  eg: We were having supper when the phone rang. 我们正在吃晚饭时电话响了。
  2. 过去进行时的否定式由“主语+was/were not +现在分词”构成
  eg: This time yesterday Jack was not watching TV. He was repairing his bike. 昨天这个时候，杰克不是在看电视，而是在修理自行车。
  3. 过去进行时的疑问式由“was/were +主语+ 现在分词”组成
  eg: Were you playing basketball at four yesterday afternoon? 你们在干什么昨天下午的时间啊  回答我啊?

• 过去进行时和一般过去时的区别：
  一、二者概念理解
  一般过去时叙述旧事，过去进行时描述背景。
  A、一般过去时
  1.过去状态、动作或事件
  He went to Beijing the other day.（带具体时间）
  2.过去的习惯
  a would ,used to与过去时
  would 表间断性不规则的习惯，常带频率时间
  used to 表一贯性有规律的习惯
  They used to meet and would sometimes exchange one or two words.
  He smoked a lot two years ago. （过去行为）
  bWould 用于文中不用于句首，只表过去习惯。
  Used to 表今昔对比的含义，叙述习惯动作可与would 换用。
  When he was a boy , he would often go there . （叙述过去）
  She isn't what she used to be. (今昔对比)
  c 表示状态时一般只用used to
  Tom used to be fat /There used to stand a tree there. (状态)
  dwas (were) used to +ving表示“合适于，适应于…..”
  He used to work at night . (“习惯”表经常)
  He was used to working at night. (习惯表适应)
  3.过去的经历，平行动作，依此事件用一般过去时。
  He sat there and listened to the radio.(依此发生)
  4.客气委婉的语气，用于情态动词，助动词和want , wonder , hope 等
  How did you like the film? / Could you help me?

  B. 过去进行时
  1.在过去某阶段或某一时刻正在发生
  What were you doing at 8:30 last night? (过去某时刻正在发生)
  2.性动词用过去进行时表示按计划、打算
  During that time he was going with us.(表示打算)
  3.lways ,often ,usually 等连用表喜爱，讨厌等感情色彩。
  He was always Changing his mind.

  二、区别
  A. 进行时表某一行为的“片断”一般时表示行为的“整体”和存在的状态。
  I was reading the book at that time. (未读完，“读”的片段)
  I read the book yesterday. (已读完，表整个“读”)
  B、一般持续时间状语多与进行时连用
  It was raining all night.(优先用was raining ,rained 为持续动词，故也可使用)
  He was writing a letter the whole of afternoon. (短暂动词与持续时间连用，表反复，连续发生，不可用一般过去时)
  C、while 时间状语从句中用短暂动词时只能用进行时。
  例：He broke a chair while he was jumping up and down.
  D、While 所在主从句动作大致持续相等时主从句一般都用进行时，但若是持续动词可都用一般过去时，两个动作一长一短时短的用一般时，长的用进行时。
  I was cooking the dinner while he was playing the piano.(平行)
  I cooked the dinner while he played the piano.
  I saw him while I was walking to the station.