談談虛擬語氣
如果你看到下列的句子，你會認為它們是正確的還是錯的呢？
1.I wish I were a bird.
2.We request that you be here tomorrow.
也許你會說:"哈哈，第一句的 I were 錯了，應該是 I was；而第二句中的 you be是什么東東呀？不是 you are, 也不是 you will be, 什么 you be?!"其實上面的句子都是一種稱為 Subjunctive 類型的句子。Subjunctive Mood 有的書譯為"假設語氣"，雖不很貼切；但在相當大的程度上，告訴我們這種句子的特點。Subjunctive Mood中文譯作"虛擬語氣"，似乎不及"假設語氣"那么容易明白。它是一種動詞形式，表示說話人的某種假設、愿望、懷疑、猜測、建議等含義。基本上，虛擬語氣可分為虛擬現在(Subjunctive Present)和虛擬過去(Subjunctive Past)兩種；但它們和時態(Tenses)上所指的現在時態(Present Tense)和過去時態(Past Tense)是有所不同的。
一、虛擬現在(Subjunctive Present):
虛擬現在的句子，在任何時候都要用動詞的原形(root form)，就算是第三人稱(he,she, it)也是如此。如：
1.1 現在時態(Simple Present): (右邊為虛擬語氣)
　I work ---- I work
　you work ---- you work
　he works ---- he work (注意到了嗎，是 work，不是 works)
　she works ---- she work (不是 she works 喔）
　it works ---- it work　(同樣不是 it works 喔)
　we work ---- we work
　they work ---- they work 
1.2　現在進行時態(Present Continuous):(右邊為虛擬語氣）
I am working ---- I be working (注意用的是 be，怪怪的!)
　you are working ---- you be working
　he is working ---- he be working
　she is working ---- she be working
　it is working ---- it be working
　we are working ---- we be working
　they are woring ---- they be working
1.3　現在完成時態(Present Perfect):(右邊為虛擬語氣)
I have worked ---- I have worked
　you have worked ---- you have worked
　he has worked ----- he have worked (用的還是have喔)
　she has worked ---- she have worked
　it has worked ---- it have worked
　we have worked ---- we have worked
　they have worked ---- they have worked
1.4　現在完成進行時態(Present Perfect Continuous):(右邊為虛擬語氣)
　I have been working ---- I have been working
　you have been working ---- you have been working 
　he has been working ---- he have been working　(是 he have, 不是 he has )
　she has been working ---- she have been working
　it has been working --- it have been working
　we have been working ---- we have been working
　they have been working ---- they have been working
談談虛擬語氣(Subjunctive Mood)（二）
二、虛擬過去(Subjunctive Past)
虛擬過去的動詞無論在什么情況之下都要用過去復數形式。如：動詞 be，在虛擬過去中要用 were。
2.1　過去時態(Simple Past):(右邊為虛擬語氣)
　I worked ---- I worked
　you worked ---- you worked
　he worked ---- he worked
　she worked ---- she worked
　it worked ---- it worked
　we worked ---- we worked
　they worked ---- they worked
2.2　過去進行時態(Past Continuous):(右邊為虛擬語氣)
　I was working ---- I were working （注意是 I were）
　you were working ---- you were working 
　he was working ---- he were working (是 he were 喔)
　she was working ---- she were working
　it was working ---- it were working
　we were working ---- we were working
　they were working ---- they were working
2.3　過去完成時態(Past Perfect):(右邊為虛擬語氣)
　I had worked ---- I had worked
　you had worked ---- you had worked
　he had worked ---- he had worked
　she had worked ---- she had worked
　it had worked ---- it had worked
　we had worked ---- we had worked
　they had worked ---- they had worked
　(耶，全部都用 had ! )
2.4　過去完成進行時態(Past Perfect Continuous):(右邊為虛擬語氣)
　I had been working ---- I had been working
　you had been working ---- you had been working
　he had been working ---- he had been working
　she had been working ---- she had been working 
　it had been working ---- it had been working
　we had been working ---- we had been working
　they had been working ---- they had been working
談談虛擬語氣(Subjunctive Mood)（三）
三、簡單的祝愿和命令：
3.1　祝愿
　1.May you be happy. (注意那個be)祝你幸福。
　2.May you have a good time.
　3.May the friendship between us last long,
　4.Have a good journey! 祝你旅途愉快！
3.2　命令
　注意：
1.命令虛擬語氣只能用在第二人稱(you)，而且通常省略主語(也就是you)。
　2.句子尾通常加上感嘆號：！
　3.虛擬語氣動詞用一般現在時態(Simple Present)，如：work, be , go
　4.否定形式的命令語氣，可用助動詞 do，加上 not。
　1.Work !
　2.Work harder !
　3.Be more alert ! (虛擬語氣動詞 Be) 
　4.You go out !
　5.Do not work so hard. (do not 表示否定的虛擬語氣)
　6.Don't be afraid. (口語中常用don't 代替 do not)
談談虛擬語氣(Subjunctive Mood)(四)
四、在現在時態句里，用情態動詞(Modal Verb)的過去時態(could,might,should,would)表示說話人的謙虛、客氣、有禮、委婉等：
1. Would you be kind enough to show me the way to the post office.(情態動詞 would,表示客氣有禮)
2. It would be better for you not to stay up too late.(表示委婉)
五、虛擬語氣在賓語從句(Subordinate Clasue)中的用法：
5.1 在wish后的虛擬語氣賓語從句(可省略它的that)：
　　表示：
a.和現在的事實相反；
　　b.和過去的事實相反；
　　c.對將來的主觀愿望。
5.1.1 現在情況的虛擬，從句用過去式或過去進行式(時間上是同時的)：
　1. I wish (that可省略,下同)I knew the answer to the question.(wish, 動詞過去式 knew)
　　 我希望知道這個答案。(事實上是不知道)
　2. I wish it were spring in my hometown all the year around.(wish, were)
　　 但愿我的家鄉四季如春。(事實上不可能)
　3. I wish I were a bird.(wish, were)
　　 但愿我是只小鳥。(事實上不可能,難道是鳥人？呵呵) 
　4. When she was at the party,she wished she were at home.
　　 (wished,過去虛擬動詞were)(事實上并不在家)
　5. Now that he is in China, he wishes he understood Chinese.(wishes,過去虛擬動詞understood)
　　 現在他在中國，他希望能懂得中文。(事實上并不懂)
　6. When we begin the trip, they will wish they were with us.
　　 (will wish,過去虛擬動詞were)(事實上并不和我們在一起)
5.1.2 過去情況的虛擬，從句動詞用"had + 過去分詞"（時間上較前):
　1. I wish (that可省略，下同)I hadn't wasted so much time.
　　 我后悔不該浪費這么多時間。(事實上已浪費了)
　2. He wishes he hadn't lost the chance.
　　 他真希望沒有失去機會。(其實已失去)
　3. We wished he had spoken to us.
　　 (wished，had + spoken)(事實上他并沒同我們講)
　4. I wish you had called earlier.
　　 (wish, had + called)(事實上已遲了)
　5. They will wish they had listened to us sooner.
　　 (will wish,had + listened)(事實上并不如此) 
5.1.3 將來情況的虛擬(表示將來的主觀愿望)，從句動詞用"would/should/could/might + 動詞原形"(時間上較后):
　1. I wish it would stop raining.(虛擬動詞would+動詞原形stop)
　　 我希望雨能停止。(事實上雨還在下著呢)
　2. I wish you would be quiet.(would + be)
　　 我希望你安靜一些。(事實上那家伙還在吵著呢)
　3. You wished she would arrive the next day.(would + arrive)
　　 你希望她第二天會到。(事實上她還沒到)
　4. I wish she would change her mind.(would + change)
　　 我希望她會改變主意。(呵呵，女孩子可沒那么容易就改變主意喔)
　5. He will wish we would join him the following week.(would + join)
　　 (只是希望我們和他在一起，實際上還沒在一起)