虚拟语气
1 有关虚拟语气的一些问题
1 有关虚拟语气的一些问题
有一位读者来信问：
(1)We suggested that we put off the meeting till next Monday.
在这一句中，put off 之前是否省去了should? TOEFL 例句中说不可加上should, 否则算错。应如何理解？
这里的确有一个英国英语与美国英语不尽相同的问题。在英国英语中，例（1）中put off 之前可用助动词should, 亦可不用，其意义不变。但在美国英语中，像例（1）这样的句子，一般只用现在虚拟式put off, 其前不加助动词 should。 TOEFL 即是以此标准进行考试的。但应指出，例 （1）用put off 也好，用should put off 也好，它们都是独立的虚拟时式，所以不存在put off 之前是否省去should 的问题。不少读者对should put off 这样的虚拟式比较熟悉，而对put off 这样的现在虚拟式似乎有点陌生，所以我们愿借此机会谈谈现在虚拟式的问题。
什么是现在虚拟式呢？ 简言之，现在虚拟式（present subjunctive)是一种独立的虚拟时式，它区别于过去虚拟式（如were）, 其形式与动词原形相同。这种虚拟式比较古老，常用在各种从句之中，如：
(2)It is best that he go .（用于主语从句）
(3)The idea is that the education for the oversixteens be improved . （用于表语从句）
(4)I desired that the action be postponed . （用于宾语从句，这里谓语动词虽是过去式 desired, 其后的从句仍须用虚拟式）
(5)If there be none, never mind it.（用于条件状语从句，比较文气，现已少用）
(6)It is high time that he go . （用于定语从句，现多用过去虚拟式went 或were going）
现在虚拟式也可用在独立句中，多表愿望，如：
(7)Long live the People's Republic of China!
(8)God forbid !
(9)The devil take you! （亦可认为省去首词 may）
有时还可引导一个独立句，在形式上与祈使句相似，如：
(10)Be it so.
(11)Let them take care what they say.
(12)Suffice it to say that we have been delayed by storms.
注意： 我们常用的please （请）本也是现在虚拟式，（现在已被唤作感叹词），如：
(13)Please forgive me, everybody.
上述结构还常用作时间状语或让步状语，如：
(14)She will be 18 years old come Easter. （用于时间状语）
(15)Home is home be it ever so homely. （用于让步状语）
有一些习语中的动词原形实际上也是现在虚拟式，如：
(16)Sink or swim , I shall undertake it. （sink 与swim 之后省去了主语I，是古时的让步状语从句结构）
同一位读者还提出一个颇为重要的问题。他举了这样一道小试题：
(17)_____, I would not have gone.
全句意谓“我要是你的话，当时是不会去的”。要求写上所缺的话填四个词。答案是 If I were you。但请问填作 Had I been you 行不行？ 为什么？
不行，这里必须填If I were you, 因为它已成为一种固定的说法。其中的were 不但不可改为had been, 也不可代之以不很正式的过去虚拟式was, 这正如固定说法as it were 中的were 不可改变一样。
山东的一位读者来信问：
(18)Some （ecologists）believe that without drastic measures Europe's lands and forests would one day become acidic waste lands.
这一句中的without drastic measures 起什么作用？
例（18）中的without drastic measures 是一短语，在句中用作条件状语，意谓“如不采取严厉措施”，所以其后的谓语动词用的是表结果的过去将来虚拟式would become。这种不用if 从句所表的条件叫作含蓄条件。除用介词短语表示含蓄条件外，还可以用其它词语表示含蓄条件，如：
(19)Ordinarily, they would have investigated the case immediately. （副词 ordinarily 表示含蓄条件）
(20)Horsewhipping would be too good for such a scoundrel. （名词horsewhipping 表示含蓄条件）
(21)Not to be moved by it would require a heart of stone. （不定式短语 not to be moved by it 表示含蓄条件）
(22)Anyone seeing them together might have been excused for taking her for Robbie's somewhat older sister. （分词短语seeing them together 表示含蓄条件）
(23)What would you think of my sister singing? （my sister singing 在此 = if my sister sang）
以上句子有的含蓄条件皆为非真实条件。含蓄条件也可以是真实条件，如：
(24)A little drink will work wonders in a cowardly man. （a little drink 表真实含蓄条件）
(25)Let's go. We'll be lucky to get there before dark. （to get there before dark 表真实含蓄条件）
有一位北京的读者问到it is important （essential, etc.）后接的主语从句是否必须用虚拟语气？ 可否用直陈语气？
如按语法规则讲，it is important （necessary, essential, natural, strange, etc.）后接的主语从句如不表事实而表主观态度，则皆应用虚拟语气，可是事实上，除在正式文体中外，直陈语气已不罕见，如：
(26)It's important that we are not drawn into the same group as Serbia and Herzegovina, because that will mean we'll have trouble getting to the semifinals.
(27)It was essential that she learned quickly.
这说明在当代英语中，或者说在现代英语中，确实有一种虚拟语气被代之以直接语气的趋问。这种趋向似乎也侵入了demand, suggest 等动词后接的宾语从句之中，如：
(28)She demands that Jacques goes on.
(29)Most of those surveyed suggested that the State makes legislation defining job change as a legitimate right.
这位读者还问：有人说在
(30)It's time we left.
这一句中只能用left, 对吗？
不对。下面的说法也都正确：
(31)It's time we leave .
(32)It's time we should leave .
(33)It's time we were leaving .
这位读者又问道：虚拟语气除用在上述修饰 time 的定语从句外，还可以用在别的定语从句中吗？
虚拟语气也可以用在其它定语从句之中，而且并不罕见，如：
(34)Any boy who should do that would be laughed at.
(35)A man might pass for insane who should see things as they are.
(36)Some scientists thought that the dust layers on the moon were so deep and loose that they might swallow up anyone who landed there.
(37)Most of the enterprises which were asked to donate did not dare to refuse for fear the units they annoyed would take revenge.
有一位中学教师来信要求解释下列句中的“would have+过去分词”：
(38)“The bomb would probably have destroyed the plane soon after takeoff,” police said.
(39)If you would have come sooner you could have helped us.
(40)I wouldn't have said that if I had thought it would have shocked her.
(41)I wouldn't have dreamed it.
(42)“My mother never considered her children's education,” said the man, who didn't have any schooling, “since she was not even sure if she could raise us. My father thought that if we could make our own living after growing up he would have done his duty.”
(43)— He had an accident last — when would it have been?
— About May.
(44)“Do you know how near the edge you are?” he rasped. “Look! One step beyond that stone and there'd have been no question of keeping you here.”
“would have+过去分词” 结构用法较多，而且也不都是虚拟时式，所以遇到它时需要进行具体分析。现按上述例句的顺序逐一分析如次：
例（38）中的would have destroyed 显然是我们常见到的表示与过去事实相反的过去将来完成虚拟式，其所在的主句表示结果，其条件从句大概是if it had not been discovered,被省去了。
例（39）中would have come 是虚拟式，但已古旧，应代之以 had come。
例（40）中的虚拟式would have shocked 可以代之以虚拟式would shock，二者可以通用，其意义亦无甚不同，但其着眼点却不一样。前者是从说话人说话时的角度看的，后者是从had thought 所表的时间看的。但须注意，后者如可能被理解为直陈语气时，则须用前者。
例（41）中的wouldn't have dreamed 的用法与例（40）中的would have shocked 相同，只不过它是否定结构而已。这里自然也可用虚拟式wouldn't dream，其与wouldn't have dreamed 的区别也是在于着眼点不同。
例（42）中的would have done 不是虚拟语气，而是直陈语气。换言之，would have done在此是过去将来完成时，用在谓语动词 thought 后接的间接引语that 从句中。过去将来完成时表示在过去将来某一时间以前发生的动作。这里that 从句中的过去将来某一时间即暗含在if从句之中。
例（43）中的 would have been 也不是虚拟时态。would 在此是一情态动词 （或叫做情态助动词），表示较大的可能性，相当于汉语“大概”。would have been 指过去，正如 might （could）have been 指过去一样。when would it have been 这一疑问句的意思是： 这大概是什么时候的事？
例（44）中’d have been 即=would have been。 按照一般教学用的语法规则，这里应用would be, 以表示与过去将来事实可能相反的虚拟结果。但这里却用了would have been。
据笔者所见，这种过去将来完成虚拟式似乎多用于美国英语中，而且并不鲜见，值得我们注意。其用这种虚拟式的原因可能有二： 一是美国英语中往往保存了一些古旧的表现法，而用过去将来完成虚拟式表示过去将来即是其中之一；二是这种虚拟式的虚拟性比较明显无误，而过去将来虚拟式则有被误解为直陈语气的可能。再举一例，供参考：
(45)She was a pretty baby. She would have grown up to be a beautiful woman. He wondered what her life would have been like. Would she have gotten married and had children? Or perhaps become an artist or a teacher or a business executive? Would she have been rich or poor? Happy or unhappy?（此例中的话皆是一位医生接生后的设想。省去的虚拟条件是“如果这个婴儿能成活的话”）
2 再谈有关虚拟语气的问题
读者们来信还问到一些有关虚拟语气的问题，现答复如下：
问一：虚拟时式到底有多少种？ 请举例说明好吗？
虚拟语气的时式通常共有七种。其中有一些与直陈语气的时式相同，二者切不可混淆。现将这七种虚拟时式举例说明如下：
1. 现在虚拟式（即动词原形），可用于一切人称和数，如：
(1)If it rain , I'll not go.（在此指将来，这种用法已较古旧）
2. 过去虚拟式，即动词的过去式，但be的过去式为were。过去虚拟式也可用于一切人称和数，如：
(2)If it rained , I would not go. （在此指将来）
3. 过去完成虚拟式，即“had+过去分词”，与直陈语气的过去完成时完全相同，但二者的语气不同。过去完成虚拟式亦可用于一切人称和数，如：
(3)If it had rained , I wouldn't have gone.（指过去）
4. “should +动词原形”，可用于一切人称和数，如：
(4)If it should rain , I'll not go.（指将来）
5. “should have+过去分词”，可用于一切人称和数，如：
(5)If the ship should have left at noon it will be passing through the canal now.（指过去）
以上例句皆指用于条件从句的虚拟时式。此外，还有两种常用于结果主句的虚拟时式：
6. “should （第一人称）或would （第二、第三人称）+动词原形”，如：
(6)If I had time I should come . （美国英语用would）
(7)If he had time he would come .
7. “should （第一人称）或would（第二、第三人称）have+过去分词”，如：
(8)If I had had time, I should have come . （用 would 亦可）
(9)If he had had time, he would have come .
有些情态动词的过去式，如could, might, should （应该、竟然等）和would （愿意），亦可与动词原形或“have +过去分词” 构成虚拟时式，如：
(10)If I knew how it worked, I could tell you what to do.
(11)I said that if I had known how it worked, I could have told you what to do.
但请注意情态动词would 用于虚拟语气时，它有时并不意谓“愿意”，如：
(12)I should be very grateful if you would be kind enough to help me. （would 在此只表示一种请求）
在下面一句中，would 则非情态动词，而是助动词：
(13)If you would be patient for yourself, you should be patient for me.（if 从句内部省去了另一if 从句“if occasion should arise”，所以这里的would是一助动词）
问二：表非真实条件的if 从句可用作表语吗？
if从句表真实条件和非真实条件时，皆可用作表语，虽然不甚普通。例如：
(14)Our only problem is if someone gets that brilliant notion first. （if 从句表真实条件）
(15)It has been said that the worst thing that can happen in sports is if you expect to win and then lose. （if 从句亦表真实条件）
(16)It seems to me the best thing would be if we put a stop to the whole thing now. （if 从句表非真实条件）
问三：表示非真实条件除用if 从句外，还可用其它连词引导的从句吗？
最常用来表非真实条件的从句当然是由连词 if 引导的条件从句。但除去if 之外，英语里还有不少其它连词可以引导表非真实条件的从句。现举一些较常见的情况如下：
(17)The peasants in a thousand villages prepared to feed that city when it should be freed. （由连词when 引导）
(18)Unless she could achieve that, she would change back into Josephine Cooper again.（由连词unless 引导）
(19)He will never be able to find out her secrets, though he had strength enough to bite through iron. （由连词 though 引导）
(20)My contention is that their plan would never have been successful whatever had happened. （由连接代词whatever 引导）
(21)She has the efficient air, as though she carried the British Empire in her pocket. （由短语连词 as though 引导）
(22)Some young people's true sex is often not detected until he or she become ill or wounded. （由连词 until 引导）
问四：请问下面一句话中的if从句为什么用were：
(23)If I were not busy, I would have come.
不少读者提到这个问题。按照语法规则，表示与过去事实相反的情况时，if 从句应用过去完成虚拟式。但这只是指一般情况而言。而例 （23）的if 从句用过去虚拟式were 表示与过去事实相反，则是一种特殊情况。这种特殊情况在英语里是屡见不鲜的。但仍有一些英语语法权威不赞成这种特殊用法，例如有一位美国语言学家就认为if he were here yesterday 不及 if he had been here yesterday 好。
问五：你曾说必须说 if I were you, 但我也看见过if I was you, 如何解释？
我们在回答为什么用if I were you 而不用if I had been you 的时候，关于能否用if I was you 的问题，我们没有涉及。if I was you, 是有人说的，但尚不普通，似乎多用在美国。不过在非正式乃至正式英语中，不论在英国和美国，was 都有取代were 的趋势。was 之所以为人们所喜欢是因为它和所有的其它过去虚拟式一样，都和直陈语气中的过去式相同。换言之，唯一的一个独特的过去虚拟式were 在人们的心目中未免有点太特殊了，需要把它拉平。在英语中用was替代were的情况很多。现再举几个较为常见的例子如下：
(24)I wish I was ten years younger.
(25)If it wasn't for me, you'd have taken the wrong path a long time ago.
was 有时亦可用在正式英语之中，如：
(26)I shall act by her as tenderly as if I was her own mother.
说来也怪，在下面的句型中却只能用was, 不能用were：
(27)It's time I was in bed.
下面一些句子中的虚拟式were 在英语中虽不罕见，但它并不表示与事实相反，故应改用直陈时式was：
(28)The spokesman answered “of course” when asked if she were optimistic about the negotiations.
(29)In my childhood I admired a man if he were rich.
下面一句中的were则是一种古老的用法，现在少用或不用了：
(30)The story of the Aeneid is necessary to know, and it were best read in the version of Conington. （现多用would be）
但须注意，在as it were 和 were it not for me 等固定结构中，were 似乎仍不可代之以was。另外，不消说，用虚拟式was 时，其主语必须是单数。
问六： 有一本英文小说有这样一句话：
(31)I wish that poor Strickland had been alive.
这里为什么用过去完成时had been 而不用were?
这里用had been 或were 都可以。过去完成虚拟式有时也可用来表示与现在事实相反的情况，其非现实性(unreality)甚至还大于过去虚拟式。再如：
(32)If I had had the money I should have paid you. （这句话除可指过去外，亦可指现在）
(33)I wish I had been rich enough to give you the money.
(34)Monsieur the Marquis ran his eyes over them all, as if they had been rats come out of their holes.（这句话虽指过去，但 had been 显然替代了过去虚拟式were）
问七： 请问下面三句话的意思有何不同：
(35)I should like to have gone to the concert.
(36)I should have liked to go to the concert.
(37)I should have liked to have gone to the concert.
这三句话都表示未实现的愿望，都表示没有去音乐会。但例 （35）强调说话人现在的愿望，全句的意思是： 我现在真希望 （那时）去了音乐会。例（36）强调过去的愿望，全句的意思是：我本希望去音乐会的。至于例 （37），其意义与例 （36）完全相同，只是不但用了虚拟完成式should have liked, 而且用了不定式完成式to have gone。这种结构显然比较笨重，所以在当今英语中已不多见了。
问八： 下面一句中的宾语从句为什么用shall:
(38)Poetry is not one of those forms of literature which require that the author shall mix a great deal with active life.
这里的shall也可说是一种虚拟式，有的语法家将它唤作“现代虚拟式” (modern subjunctive)。它的含义相当于must, 语气较强。再如：
(39)We demand that this burden shall be removed.
(40)I will arrange that another consultation shall be held.
(41)The doctor insists that I shall give up smoking.
但在当今英语中，这种shall已很少用，只用于很正式的文体（如法律文件）了。现在我们多用现在虚拟式或 “should +动词原形”。
关于虚拟语气的问题，着实比较多，其它问题只好容后再谈了。
3 三谈虚拟语气问题
关于虚拟语气，还有几个问题需要回答。
问一： 你所说的七种虚拟时式中没有进行式，这是否意味着虚拟语气不可用进行式呢？
不，虚拟语气亦可用进行式，如虚拟式were即可后接现在分词构成虚拟进行式，如：
(1)I suppose it's almost time we were leaving .
(2)I would have stopped him if five men were not sitting on my chest.
should, would 等亦可后接“be+现在分词”从而构成虚拟进行式，如：
(3)Sometimes she would suggest I should be saving some of the money.
(4)—You mean you didn't hear?
—If I did, Would I be asking ?
问二： 请问下面的第二句话为什么用表与将来事实可能相反的虚拟语气？
(5)—Shall I call for you?
—It would probably save time if we met downtown. You tell me where.
这又是一种特殊情况。一般说来，虚拟语气皆用于表与事实相反或很可能相反的情况。但例 （5）中的虚拟语气则属例外。这种虚拟语气当然不强调与事实可能相反，而是强调一种非常有礼貌的请求。这种用以表示请求的虚拟语气并不少见，再如：
(6)If you were to help him, it would keep him safer.
(7)It would be best if you didn't write them down, but carry them in your mind.
这种表示请求的虚拟语气还可以与祈使语气连用，如：
(8)If you enjoyed this book, just send your name and address and ten dollars to us.
有时这种虚拟语气则表示一种愿望，如：
(9)Cissy Topping would make you happy. And if you married her, it would make me happy.
（这是一位母亲对她的儿子讲的话）
问三：虚拟语气的时态有时与直陈语气的时态互为影响，有时相互之间又似乎没有影响，这到底是怎么一回事？ 请解释。
这个问题，用语法术语来说，即是一个虚拟语气与直陈语气二者的时态何时有时态一致的问题。这个问题比较复杂一些，这里只能做一般性的讨论。
全句的谓语动词如属直陈语气，其时态对从句的虚拟时态一般没有影响，即没有时态一致的问题，如：
(10)It is （was）important that she have confidence in herself. （虚拟式have 不受谓语动词直陈式is 或was的影响）
(11)I suggest （suggested）that he should go tomorrow. （虚拟式should go 不受谓语动词直陈式suggest 或suggested 的影响）
(12)I wish （wished）I hadn't been so forgetful.（虚拟式hadn't been 不受谓语动词直陈式wish 或wished的影响）
(13)A prize of one hundred thousand florins has （had）been promised to him who should grow the black tulip. （虚拟式should grow 不受谓语动词直陈式has 〈或had〉 been promised 的影响）
但在间接引语中，如强调时间性，则须遵守时态一致的原则，如下面句中的直接引语的虚拟时态：
(14)“If I knew how it worked, I could tell you what to do，” he said.
须变为下面的间接引语的虚拟时态：
(15)He said that if he had known how it worked, he could have told me what to do.（注意how 从句中的时态不变）
但如不强调时间性，直接引语变为间接引语时，其虚拟时态则可不变，如：
(16)“If I knew the answer to all your questions, I'd be a genius，” he said.
可变为：
(17)He said that if he knew the answer to all my questions, he'd be a genius.
如果句中的谓语动词属虚拟语气，其后从句的直陈语气则多受其影响，即现在时态应随之变为过去时态，如：
(18)I would think he was wrong. （从句应用was, 试比较：“I think he is wrong.”）
(19)It would seem that she was right.（从句应用was, 试比较：“It seems that she is right.”）
(20)If we weren't living in the twentieth century, I would think you were a sorcerer. （would think 后的从句用过去式were）
(21)—You keep poultry then.
— I should think we did keep poultry.（由keep 变为did keep）
— You have got pigeons too, I see.
— Yes, I shouldn't wonder if we had got pigeons too! （由have got 变为had got）
但有时人们并不遵守这一时态一致的规则，如：
(22)I should say that this book meets your requirements. （meets 未变作met）
下面表愿望的两句中的现在式一般皆不变作过去式：
(23)If you knew they have been for me! （have been 不变为had been）
(24)Oh, if I knew how he is suffering. （is 不变为was）
问四：为什么会有混用虚拟语气与直陈语气的现象？
在同一句中，说话人有时会中途改变语气，这就是混用语气的原因。有时说话人在条件从句中用了虚拟语气，强调现实性小，主句中却改用了直陈语气，又强调现实性大了，如：
(25)Surely if they had been zealous to pluck a brand from the burning, here was a noble opportunity.（先在条件从句中用虚拟式had been, 后在主句中用直陈式was）
(26)I am not bad looking if my skin were not so sallow. （先在主句中用直陈式am, 说自己不难看，后在条件从句中用了虚拟式were）
下面一句中的混用语气现象已属司空见惯的了：
(27)Should there possibly be any such case, I have not seen it. （从句中用虚拟式“should+动词原形”时，主句则常用直陈语气）
有时恰恰相反，说话人在条件从句中用直陈语气，强调现实性大，在主句中用虚拟语气，又强调现实性小，如：
(28)If he lost his health and lost his job, we would all have starved. （从句用直陈式 lost，主句用虚拟式would have starved）
(29)If you fall into his hands, you'd soon have known the difference. （从句用直陈式fell, 主句用虚拟式would have known）
(30)If you don't come down sharply on some of those people, they'd soon be asking for the earth. （从句用直陈式don't come, 主句用虚拟式would be asking）
注意下面一句中的从句是由when 所引导：
(31)When it rains you wouldn't think it was the same place as on a fine day. （when 从句用直陈式rains, 主句用委婉的虚拟式wouldn't think）
问五：有时虚拟条件从句中的动作与虚拟结果主句中的动作在时间上并不一致，这时应如何用表不同时间的虚拟时态？
当虚拟条件从句所表的动作或状态与虚拟结果主句所表的动作或状态在时间上不一致时，必须用表不同时间的虚拟时态。其用法应视具体情况而定，例如：
(32)If the weather had been more favourable, the crops would be growing even better. （条件从句用指过去的过去完成虚拟式，结果主句用指现在的过去将来虚拟式）
(33)If he had left earlier, he would arrive home this evening. （条件从句用指过去的过去完成虚拟式，结果主句用指将来的过去将来虚拟式）
(34)If he were my son, I would have given him a spank on the bottom. （条件从句用表经常的过去虚拟式，结果主句用表过去的过去将来完成虚拟式）
(35)Even if he were my brother, I would expose him.（条件从句用指经常的过去虚拟式，结果主句用指将来的过去将来虚拟式）
关于虚拟语气，就谈到这里。
4 委婉说法的比较
有一读者问： 我认为 if you should go to town 要比 if you go to town 委婉客气，但不知它与 should you go to town 相比时，是否二者同样委婉，只不过后者较为文气而已？
据一位英语语法家说， should you see him 要比 if you should see him 更为委婉。他将下列7种说法根据委婉程度的递增次序排列如下：
(1)If you see him
(2)If you should see him
(3)Should you see him
(4)If you happen to see him
(5)If you should happen to see him
(6)Should you happen to see him
(7)Should you by any chance happen to see him
顺便说一下，上述7种说法之所以一个比一个委婉客气，完全是由于其可能性一个比一个小的缘故。
5 关于虚拟式“should+动词原形”
有一读者问： 有这样一道选择题：
(1)I know that it will be difficult to pick him out in such a crowd, but if you_________happen to see him, give him this packet.
A. would B. might C. should D. could
答案为C，但我不知其中缘故，请赐教。
这一道题显然要求你用虚拟语气来回答；如可用直陈语气，那就在happen之前什么也不用填写了。
这里选should的原因在于：英语里有一种“should+动词原形”的虚拟时式。它常用于条件从句，表示将来有发生某一事件的偶然可能性，should本身无词义，其结果主句常用直接语气，如：
(2)If it should rain , he will not come. （也可以用would代替will）
结果主句亦可用祈使句，上述句（1）即是一例，再如：
(3)If you should meet Henry, tell him I want to see him.
would, might, could亦可用于条件从句中，但它们都有各自的情态意义，故不可与意为“碰巧”的happen to连用。
6 这里常用过去一般虚拟式had
有一读者问： 有这样一道选择题：
It's high time that we_________breakfast.
A. had B. to have C. have D. having
答案是A，为什么不选C?
这里习惯上常用虚拟语气had，虽然虚拟语气have也不算错。
7 这里也常用过去一般虚拟式
有一读者问： 有这样一道选择填空题：
(1)I would rather_________Switzerland the week after next.
A. they are leaving for
B. they leave for
C. they left for
D. they will leave for
请问用哪一个填空合适？ 为什么？
这里应填以C，即they left for。在较古的英语中亦可用they should leave for或they leave for，但现已废弃，或是很少见了。对于我国学生来说，当然应该用过去式left。不过，应该指出的是： 不论用上述哪一种时态，它们皆属于虚拟语气。为什么要用虚拟语气呢？ 这是因为主句中的would rather是虚拟语气，表示一种选择性的主观愿望。说来有趣，would rather本与would无关，而是从虚拟过去式had rather变来。 在当代英语里，偶尔仍可遇到 had rather，不过较为文气罢了。我国学生应该多用would rather，少用或不用had rather。在口语中，则常用缩略式'd rather。它的主要用法有二：
1. 后接不带to的不定式，如：
(2)I'd rather like a cup of tea.
(3)I would rather die than yield.
(4)Would you rather stay here or go home?
2. 后接不用连词的名词性that从句，从句的谓语动词用过去式，如：
(5)I'd rather you went home now.
(6)Don't come tomorrow. I'd rather you came next week.
(7)He says he'd rather you came to him, darling.
8 这里应选not, smoke
有一读者问：有这样一个选择题：
(1)The doctor suggested that he _____.
A. will not smoke B. not smoke
C. would not smoke D. did not smoke
该题的答案是B。但我认为应该是 should not smoke 或do not smoke。我这样理解对吗？
不完全对。在这道选择题中，只可填B，即not smoke。 should not smoke 也对，但它不在四项选择之内。应当记住，在suggest, demand, ask 等动词之后的宾语从句中，虚拟式应用“should +动词原形”或只用动词原形（即所谓现在虚拟式）。前者的否定形式是“should not +动词原形”；后者的否定形式必须是“not + 动词原形”（但动词原形be的否定形式则可用not be, 亦可用be not）。顺便指出，现在虚拟式否定结构常用于正式文体中。再如：
(2)I would like to suggest that newspaper reporters not write this kind of article.
(3)She insisted that Harry not know .
除上述宾语从句可用现在虚拟式的否定结构外，其它一些从句亦可用此种结构，如：
(4)It is essential that this mission not fail . （用在主语从句中）
(5)He spoke on condition that he not be identified . （用在状语从句中）
最后，应该指出，在当代英语里，尤其在美国，suggest, demand等后的宾语从句中亦可用陈述句does not smoke。
9 为何选用be heated?
有一读者问： 有这样一道选择题：
(1)One of the requirements for a fire is that the material_________to its burning temperature.
A. were heated B.must be heated
C. is heated D.be heated
我选的B，而答案是D，请问我错在哪里？
这里须选用be heated （=should be heated），因为这种由that引导的表语从句的谓语须是“虚拟式（should)+动词原形(should亦可不用）”。上述句型的主语常常是表要求或建议的名词如requirement, suggestion, proposal, request等，再如：
(2)My suggestion is that we （should）tell him.
(3)Our request is that he （should）be left alone.
10 这里的would never have been并不表与将来的事实相反
有一读者问： 有这样一句话：
My contention is that the government's plan would never have been successful whatever had happened.
这里的虚拟式跟将来相反，为什么都用的是与过去相反的虚拟式呢？
这里的虚拟式仍是指与过去的事实相反的假设。你可能被连系动词is误导了。这里用is并不说明其后虚拟式必须与将来的事实相反，而是说明说话人现在的论点是如何如何。
11 为什么这里用 were？
有一读者问： 有这样一个句子：
(1)If I were not busy, I would have come.
语法书上讲，过去虚拟式只能表与现在事实相反或与将来事实可能相反，但这里的 were 却表与过去事实相反，如何解释呢？
上述语法规则一般说是成立的，但过去虚拟式 were 是个例外，尤其在 if I were 等结构中。但也不限于这种结构，如：
(2)If you were in my position, you would have done the same thing.
(3)It was pointed out that if they were to meet the delegation, they would have obtained a totally different impression.
(4)He told her...he was going East...and hopefully she'd sign the settlement papers then, if they were drawn up in time.
另外，在一些应用 was 的情况中，有人也喜欢用 were， 如：
(5)If it were so, it was a grievous fault.
(6)If every poet were a master of phrasing, he was so.
(7)Better one spring into the broad blue river beneath him, were it not for little pale-faced Adèle who had none but him to look to.
were 的这种用法，有的语法家认为是 a hypercorrect pseudo-subjunctive 即一种矫枉过正的伪虚拟语气；有的语法家则认为它只用于 choice language 即精美文字之中，往往并不与事实相反。
与上述情况相似的还有下面句中的间接疑问句：
(8)He despatched his favourite courtier to see if she were really as charming as fame reports.
(9)It was difficult to tell whether the language were Semitic or Indo-European.
下面句中的 were 则用在让步状语从句中：
(10)Stewart was, perhaps, the most beloved member of Trinity, whether he were feeding rugger blues on plovers eggs or keeping an early chapel with the expression of an earth-born seraph.
最后，应该指出，上述 were 的用法都是比较少见的，有些甚至是不规范的。
12 这里的Were it not for可以与Had it not been for互换
有一读者问： 有这样一个句子：
(1)Were it not for their assistance, we couldn't have got over the difficulties.
可否将此句中的 Were it not for their assistance 改为 Had it not been for their assistance? 如可以的话，那么二者有无区别？
were 作为虚拟式是古传下来的一种形式，在现代英语里已逐渐用得少了。当今它主要用于表与现在的事实相反和与将来事实可能相反的条件句中。但它也间或用在与过去事实相反的条件句中，你的引文中的 were it not for their assistance 即是一例。这里的 were it not for their assistance 完全可以代之以 had it not been for their assistance, 二者在意义上并没有什么不同，只是前者稍较文气而已。但须指出，并不是所有用 were 表过去假设的情况皆可代之以过去完成虚拟式。有一些固定的说法至今仍须用 were, 如 if I were you （或 were I you）, if I were in your place （或 were I in your place）, as it were 等。就是像下面这样的句子也常用 were:
(2)If I were not busy, I would have come.
但有时习惯上却不用 were, 如：
(3)If he had been here yesterday, I would have seen him.
13 为什么这里用 was?
有读者问这样一个句子：
(1)He heard a noise as if someone was breathing.
《现代英语语法手册》上说“由 as if 所引导的状语从句表示比较或方式时，从句的谓语动词用虚拟语气。动词形式用过去式 (be 用 were)或 had+过去分词”。但上述引文却用 was 而不用 were, 这是为什么？
《现代英语语法手册》讲得没有错，许多语法书都这样说。但它们皆指规范英语而言。在不很规范或不很正式的英语里，as if 之后则常用过去虚拟式 was 代替 were, 再如：
(2)All this was over twenty years ago, but it's as if it was only yesterday.
(3)All shook their hands and were very grave; for it seemed as if there was no hope.
这里有必要指出， as if 从句如有真实性，即如表一事实，则可用普通时态，如：
(4)He acts as if he is in love with her.
(5)She looks as if she will be like you when she grows up.
这样说来，下面一句，孤立地看，就有歧义了:
(6)She treated me as if I was a stranger.
这里的 was 可能是一虚拟时态（无真实性），也可能是一普通时态（有真实性）。
这样说来，孤立地看，上述句（1）与句（3）也都会有歧义了。当然，在一定的上下文中，上述例句大都是不会有歧义的。
14 这里的shall 作何解释呢？
有一读者问：
(1)Is she going to keep a vigil till that time shall come?
在这一句中的till 从句竟用了shall, 不知是何缘故？
这里的shall come 不是直陈时式，而是一种虚拟时式。这种虚拟式现在已不常用，只偶尔出现在较古旧的英语中。在当代英语中，shall 多被 should 或直陈时式所代替。再如：
(2)Do my errand when it shall be most convenient for you in the course of the day. （shall 用在when 引导的状语从句中）
(3)There is much to be done before every child in the country shall speak English as could be wished. （shall 用在before 从句中）
(4)The author's idea is, in case I shall render a favourable opinion, to offer the story to a magazine. （shall 用在in case 引导的条件状语从句中）
这种古旧的shall还可用在定语从句中，如：
(5)The same circumstance may make one person laugh which shall render another very serious.
它也可以用在名词性从句中，如：
(6)Whoever shall offend, shall be punished. （shall 用于主语从句）
(7)I am determined she shall have no cause to complain.（shall 用于宾语从句）
15 为什么答案是 be it?
有一读者问： 有这样一道选择题：
(1)The business of each day,_________selling goods or shipping them, went quite smoothly.
A. it being B. be it C. was it D. it was
答案是 be it, 为什么？
be it...or... 是一种倒装的省略结构，等于whether it be...or... （但省去 whether 时 it be 即须倒装），其意是“不管（或无论）是...或是...”。再如：
(2)Be he friend or foe, the law regards him as a criminal. （亦可说 Whether he be friend or foe）
亦可用 be they...or..., 如：
(3)In the case of opera, the composers wrote their music following the original texts, be they in Italian, French or German.
下面是用 whether it be...or...的一例：
(4)Nothing, whether it be wars or political campaigns, had separated them. But today they were to part company for ever.
在语法上，这种 be 被称作“现在虚拟式”，当今比较少用，一般只用在较正式的书面语中，现将现在虚拟式 be 的一些其它用法举几例如下：
(5)Be it so. （或 So be it.）
(6)Home is home be it ever so homely.
(7)She has beauty still, be it not in its heyday, it is not yet in its autumn.
(8)Far be it from me to come between Grimshaw and his pleasures.
(9)To her credit, be it said, she never once counted on Hurstwood.
(10)If it will add anything to your happiness, I shall go through it, be it to my death.
(11)I'll work all night if need be .
(12)It is vital that we be present.
(13)In order that this measure be useful, it must be put into force at once.
16 'da broke何意？
有一读者问： 有这样一句话：
(1)If I'da broke my neck I'd be dead.
如何解释’da broke?
这是不规范的美国口语。I'da broke=I would have broken。 would have broken在美国口语中常等于表与过去相反的虚拟式had broken。再如：
(2)If you would have come sooner you could have helped us.
17 如何理解as soon as look at you?
有一读者问： 我在英国著名作家Graham Greene所写的小说《布莱顿硬糖》(Brighten Rock)中遇到这样一个句子：
He'd kill you as soon as look at you if he thought he wasn't safe.
这句话不难理解，但如何分析as soon as look at you?
这是口语化的一种说法。这里的第二个as是连词，让我们姑且认为其后省去了主语he吧。
18 关于as if从句中的时态问题
有两位读者来信问到as if从句的谓语动词应用什么时态的问题。一位读者说有这样一道选择题：
(1)He knew nothing about the matter, but he talked as if he_________it.
A. knows B. knew C. had known D. would know
请问应选B还是C?
另一位读者说，有这样一句话：
(2)Holding his head high, he walked past the pole and the soldiers as if they didn't exist.
请问这里的as if从句为什么不用与过去事实相反的过去完成时had not existed?过去一般虚拟式不是表与现在事实相反吗？
首先必须指出，上述句（1）与句（2）as if从句中的过去一般时knew和didn't exist不是直陈语气，而是虚拟语气。如何解释这种过去一般虚拟式呢？ 有一位外国学者说这种过去一般虚拟式是作者当时（写作时）的一种想象，他将他当时的想象用于过去的叙述中了。我们觉得这一看法是合理的。
关于as if从句的谓语动词应用什么时态，在中国学生中，可能是一个带有普遍性的问题。
首先有一个as if从句应用什么语气的问题，曾有语法家认为as if之后必须用虚拟时态。当今这种抱残守缺的人，即使有，恐怕也不多了。绝大多数语法家都认为，as if之后既可用虚拟语气，亦可用直陈语气。而语言实际也是如此。虚拟语气表与事实相反或很可能相反，直陈语气则表有一定的现实性。
在未谈用什么语气之前，必须指出，as if从句所用的时态，与主句所用的时态是没有什么必然联系的。换言之，不管主句用什么时态，现在时态也好，将来时态也好，过去时态也好，都不会对as if从句的时态产生什么影响。例如：
(3)He looks as if he were ill.
(4)He will look as if he were ill.
(5)He looked as if he were ill.
(6)He had looked as if he were ill.
以上四例的主句用了四个不同的时态，as if从句则可以不变应万变，皆用were。这是为什么呢？ 答案是：as if从句所表示的比喻或想象，完全是说（写）话人在说（写）话时所作的比喻或想象，与主句所表的情景（现在、过去或将来的）无关。
现在让我们开始探讨一下as if从句应用什么时态，先从虚拟时态谈起吧。
as if从句最常用的虚拟时态就是过去一般时。这种时态表与现在的事实相反，也就是表说话人当时所认为的与事实相反，而这也就是为什么上述句（1）应用knew和句（2）用didn't exist的缘故。上述句（3）、（4）、（5）、（6）中的were也都属于这种用法。（were显然是虚拟时态；而knew与didn't exist虽与直陈语气的过去一般时的形式相同，但从上下文看，二者也是虚拟时态）虚拟时态过去一般时所表的动作或状态与主句的谓语动词，是同时发生或存在的。
as if从句也常用虚拟时态过去完成时，但它并不表与过去事实相反，而是多表动作或状态的完成，相当于汉语的“已经，曾经，……过”等。所以它所表的动作或状态是先于主句的谓语动词发生或存在的。例如：
(7)He looks as if he had been ill. 他（现在）看上去像是病过一场似的。
(8)He looked as if he had been ill. 他（过去某一时间）看上去像是病过一场似的。
从以上两个例证可以看出，as if从句中的过去完成时，和过去一般时一样，也不受主句的动词时态的影响。再如：
(9)He looks （或looked）as if he had seen a ghost.
(10)He has （或had）known me long, but he treats （或treated）me as if he had never known me.
(11)People were scattering as if a rain had begun to fall in the room.
(12)It isn't as if I'd given him to believe that I was experienced! I made it clear that I wasn't. （It isn't as if I'd given him...was experienced是一感叹句，其意为“我压根儿就没有叫他信以为我富有经验!”）
请注意有时有人用过去完成时代替过去一般时。有人说这种过去完成时具有意外或惊异等感情色彩，如：
(13)He treated me as if I had been a stranger.
(14)I took him by the waist as if he had been a sack of bran.
不消说，上述两例中的had been皆可代之以were。
as if从句也可用过去将来一般时would+动词原形，其所表的动作或状态自然发生或存在于主句的谓语动词之后，例如：
(15)It seems as if the boat would sink .
(16)It seemed as if the boat would sink . （在一定的上下文中，would sink也可能是直陈语气）
(17)He looks as if butter would not melt in his mouth.
as if从句亦可用上述三种虚拟时态的进行式(were doing, had been doing, would be doing)，这里就恕不举例了。
as if从句也可用直陈语气的各种时态。这种时态表有一定的现实性，并不与事实相反。当今在英语中，这种用法已可谓屡见不鲜，下面只举几例即可见一斑。
(18)He acts as if he is in love with her. （现在一般时）
(19)He looked as if he was ill. （过去一般时）
(20)She looks as if she will be like you when she grows up. （将来一般时）
(21)It looks as if it is going to snow. （直陈语气表将来）
关于as if从句的谓语动词的时态，就谈这么多吧。