两种用法：
- 表与事实相反的假设情况
- 表愿望，请求，建议，命令
| Cond. time | Cond. v. | Main v. | Example |
|---|---|---|---|
| Now | past | would + v | If I saw the rabbit now, I would bite him. |
| Future (unlikely) | should + v / were to + v | would + v | If I should see the rabbit tomorrow, I would bite him. |
| Past | had + v | would have + v | If I had seen the rabbit now, I would have bitten him. |
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和现在事实相反（想要发生的状况），动词用过去式 (这里的"would"是"will"的过去式)
If I saw the rabbit now, I would bite him.
// 无论什么人称，始终用were
If I were you, I would give it to him.
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和过去的事实相反，条件去动词用过去完成式，主句动词用完成式
If I had seen the rabbit now, I would have bitten him.
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未来的条件，动词用将来时
If I see the rabbit tomorrow, I will bite him.
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未来的条件，但可能性很小，动词用 should + 动词原形 (这里的"should"是"shall"的过去式)
If I should see the rabbit tomorrow, I would bite him.
If I were to see the rabbit tomorrow, I would bite him.
一般用"wish/would rather"表示愿望
相比"hope", "wish"一般用于可能性小的情况
-
现在
I wish (that) I were a rabbit
I would rather (that) you didn't eat the carrot
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过去
I wish (that) I had eaten the carrot
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将来
I wish (that) I could eat the carrot
其他用法:
- 主句: demand, suggest, insist, order
- 从句: (should) + 动词原形
I demand/order/insist that you (should) eat a carrot
I demanded/ordered/insisted that you (should) eat a carrot
It is suggested/demanded/ordered/insisted that you (should) eat a carrot