第1个回答 2020-03-29
1. 表示与现在事实相反的情况,其句型为“ if+ 主语 + 动词的过去式( be 动词用 were ),主语 +would / could / might / should + 动词原形”。如:
If the weather were fine, we would go to Shanghai.
如果天气好,我们就去上海。(事实上天气不好)
If they had time, they would / could / might go with me.
如果他们有时间,他们就会(可能)和我一起去。
2. 表示与过去事实相反的情况。其句型为“ if + 主语 + 动词的过去完成式,主语 +would / could / should / might + have + 动词的过去分词”。如:
If I had taken his advice, I shouldn't / wouldn't / couldn't have made such a mistake.
如果我按照他的建议去做,我一定不会(不可能)犯这样的错误。
3. 表示与将来事实可能相反的假设和结果,其句型为“ if + 主语 + 动词的过去式 / should + 动词原形 / were to +动词原形,主语 +would / could / might / should + 动词原形”。如:
The glass would break if you dropped it.
杯子摔下来会打破的。(事实上没有摔下来)
If it should rain, the crops would / could / might be saved.
假如天下雨,庄稼就一定(有可能)会得救。