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。
