题目
一、单项选择题 18.__a little earlier, I would have caught the train.A. Did I leaveB. Would I leaveC. Had I leftD. Have I left
一、单项选择题 18.__a little earlier, I would have caught the train.
A. Did I leave
B. Would I leave
C. Had I left
D. Have I left
题目解答
答案
C. Had I left
解析
本题考查虚拟条件句的倒装结构。当虚拟条件句省略连词if时，需将助动词提前到句首。题目中主句使用would have caught，表明是与过去事实相反的虚拟语气，因此从句需用过去完成时的倒装形式。关键点在于判断正确时态并完成倒装。
选项分析
A. Did I leave
- 错误原因：
did是过去式的助动词，但虚拟条件句中与过去相反的情况需用过去完成时（had + 过分），而非一般过去时。
B. Would I leave
- 错误原因：
would表示将来时，但题目描述的是与过去事实相反的情景，需用过去完成时，而非将来时。
C. Had I left
- 正确原因：
had是过去完成时的助动词，符合与过去相反的虚拟语气。省略if后，将had提前到句首，构成倒装结构（等同于If I had left）。
D. Have I left
- 错误原因：
have是现在完成时的助动词，但题目要求与过去事实相反，需用过去完成时。