壹、條件虛擬
1、由連詞引導的條件從句，常用的有：
* if/unless 如果/若非
* 3. even if / even though 即便
* in case：萬壹，如：
--You should bring an umbrella with you, in case it were raining; of cause there’s no rain today
2、省略 if 後的倒裝虛擬，如：
* Were I you, What should I do?
* Had he been here five minutes earlier, he would have caught the train.
3、相關動詞分詞或短語充當連詞
* 過去分詞： provided，如：
--*We would pay the bonus provided the job had been completed on time yesterday. 如果工作在昨天按時完成的話我們會發放獎金的。
* 動詞原形：suppose (that)，如：
--Suppose (that) I were you. 要是我是妳多好）。
* 現在分詞：supposing，如：
--Supposing it were not Saturday tomorrow. 假如明天不是星期六（就好了）
4、介詞 without 短語表示的條件，如：
--Without electronic computers, much of today's advanced technology would not have been achieved. 要是沒有電腦的話，就不會取得當前這麽多的先進技術
5、but tha t除非,若不是，如：
--They would have got in touch with us two days earlier but that there had been something wrong with the line. 若不是線路有問題的話，他們兩天前就與我們取得聯系了。
二、願望虛擬
1、名詞從句
1）提出建議、發出命令、提出請求、表示見解願望，下面以suggest及其派生詞為例：
賓語從句：I suggested that he (should常常省略) leave immediately.
表語從句：My suggestion is that he leave immediately.
主語從句：That he (should) leave immediately is my suggestion
同位語從句：My suggestion, that he leave immediately, has not been adopted.
2）用在it is … that 句式表示上述意思，如：
--It is important that he that he (should常常省略) leave immediately.
2、幾種特殊的虛擬句式
* wish 從句，如：
-- I wish he knew what is happening there in his room. 要是他知道自己的屋子裏正發生著什麽就好了。（對此時此刻的虛擬）
--He wished he hadn't done it. 他想要是他沒這樣做該多好。（對過去的虛擬）
* would rather 從句
--I would rather you (should) come tomorrow.（對將來的虛擬）我寧可妳明天過來（暗含妳卻來不了。）
* it is time 從句
--It is high time you had got up to have your meal. 妳早就該起床吃飯了。（但是到現在妳還沒起來）
* had better 從句
--His mother had better he would have come the next day. 他母親寧願他第二天過來。
三、套式虛擬句
在表達某些信條的陳述或信仰的自白的時候，常用套式虛擬句。在這種虛擬句中，謂語動詞不受人稱和時態的約束，只以動詞原形出現在句子中。以下是常見的套語：
1. 表示祝福
* God belss you 上帝保佑
* God bless my life / my soul! 我的天啊! 好家夥!
* God speed you! 祝妳壹路平安!
* Long live liberty! 自由萬歲
2. 表示詛咒
* God damn you! 天殺的! 該死的!
* God forbid! / Heaven forfend!蒼天不容! 但願不會如此!
3. 表示發誓
* Far be it from me to … 我決不會…
* Suffice it to say that … 只要說…就夠了。
* Come what may / will … 不管發生什麽事情
4. 表示願望
* God grant ...! 但願...!
* So be it then. 那樣也好
* Be that as it may … 盡管這樣
5. 表示感嘆
God help him! 唉, 真可憐!
Heaven help us! 蒼天保佑！
關於虛擬語氣的時態問題
壹、條件虛擬句或特殊句式的虛擬
1、對現在的虛擬
* 主句 —— would/should/could/ought to + 動詞原形
* 從句 —— 動詞過去形式（動詞 be 壹律用 were）
2、對過去的虛擬：
* 主句 —— would/should/could/ought to + have done
* 從句 —— 過去完成式 had done
3、對將來虛擬，分三種情況：
1）實現的可能性不大 ——（should可省略，但是要註意只能用should 而不可以用其他情態動詞）do；
2）實現的可能性很小 —— 過去時（did/were）
3）根本不可能實現 —— were to do
二、名詞從句中的虛擬壹律用“should + 原形”或者省略 should 直接用動詞原形