虛擬語氣作為高考難點一直讓許多學生頭痛不已,非真實條件句中虛擬語氣的考察更是重點.許多語法書上對虛擬的講解總是涉及時態,筆者認為這極不利于學生對此知識點的理解與運用. 筆者在教學實踐作了一些嘗試,起到了不錯的效果。
一、拋開時態學虛擬
張道真實用英語語法對虛擬語氣的定義如下: 在表示一種純然假想的情況或主觀愿望時,動詞需用一種特殊形式,成為虛擬語氣. 時態與時間有密切關系,而虛擬語氣實際是對真實情況的假設,因此其表達方式必須與正常時態的表達有區別.因此,拋開時態,把其作為一種特殊表達方式來理解更容易掌握其規則.如下表中,用had done 結構表示對過去事實的虛擬表達,而不用過去完成時這一概念。因此,在學習虛擬語氣時,牢記三個時間段:過去,現在和將來。

以下句為例:She would have said more if he _______(walk) away. 從would have said可看出整個句子時間為過去,因此,按照規則,空格處應為had done結構,再結合句意,應為否定,最終正確答案had not walked 就表達出來了。
二、善于發現含蓄的條件
許多同學誤以為虛擬條件只有if可以引導,其實不然。
1. without, but for 可引導相當于的if條件。例:
But for your help, I couldn’t have succeeded.等于If you hadn’t helped me, I couldn’t have succeeded.
2. or, otherwise 相當于if條件。例:
He hesitated for a moment before kicking the ball, otherwise he would have scored a goal. 此題中,otherwise 就等于if he hadn’t hesitated.
3. 真實情況暗含的虛擬條件
虛擬語氣的表達十分靈活,學生要善于發現真實情況下暗含的言外之意。同一個句子中,既有虛擬語氣,又有陳述語氣。例:
I would go to the concert but I have no time. 從I have no time 可知其言外之意if I had time, I would go to the concert..
4. 從句也可用if it were not for /if it had not been for(若不是)來構成謂語。
If it were not for your help, we would be in serious trouble.
If it had not been for your help , we would have been in serious trouble.
三、倒裝問題的解決
虛擬語氣中倒裝問題一直是高考熱點,也是學生易錯的題型,實際上,既然可以倒裝,就可以不倒裝,許多同學更習慣讀不用倒裝的句子,即用陳述語序表達的句子。……