| if 从句 | 主句 4 + 1 | 例句 | |
|---|---|---|---|
| did/were | colud would should might |
do | If I had time tomorrow,I would discuss the new plan with you. |
| were to do | If I were to live my life over again,I would have you as my wife. | ||
| should do | If it should have rained, we would have stayed at home. | ||
第 3 类条件句是在 if 从句里设想纯粹想像的事情，在主句里讲述想像的结果，谈的是没有或永远不可能有的结果，指的是过去没有过的事情。
- If I had worked hard at school, I’d have got a better job. if 从句用过去完成时，主句用 would have/ should have +过去分词
- I’d have read that book if I could have bought it.在 if 从句中可用 could have +过去分词代替 had been able to +动词原形
suggest/insist + that + 从句 (特殊结构：should + do)用来表达建议或坚持的观点(正式语境或表达强调)
- She suggested that he should arrive early for the meeting. 当suggest表建议的时候，从句用虚拟语气，后接动词是要用-ing 形式，后接 that 从句采用一种固定的用法“should+动词原形”（should 可省略）
- He insisted that she should apologize for her behavior.
- The teacher suggested that the students should study harder for the exam.
- My parents insisted that I should go to college after high school.
- The doctor suggested that he should quit smoking for his health.