C1
S + would have + V3, but ... · S + would have + V3 + if ...
would have V3——本来愿意做却没做成的事
讲解
用来说过去的意愿或好意最终没有实现，后面常带一个 but 分句说明原因。与第三类条件句不同的是，这里的 if 分句可以完全省略，重点在于说话人当时的意愿。 常见错误：if 分句里不能用 would have：If I would have known ✗, If I had known ✓。
例句
I would have called, but my phone was dead.
我本来想打电话的，但手机没电了。
She would have helped, only nobody asked her.
她本来愿意帮忙的，只是没有人找她。
They would have won with a full squad.
如果人员齐整，他们本来是可以赢的。
We would have stayed longer, but the last train left at ten.
我们本来想多待一会儿，但末班车十点就开了。
练习
通过选择题测试你的掌握程度
高效学习“S + would have + V3, but ... · S + would have + V3 + if ...”
语法点“S + would have + V3, but ... · S + would have + V3 + if ...”（would have V3——本来愿意做却没做成的事）是 CEFR 5 级别的重要结构之一。要熟练运用这个结构，你需要弄清楚它的使用语境，并经常练习。
学习小贴士：把例句大声朗读多遍，培养自然的语感反应。然后试着结合自己的生活情境造句。用发音按钮听标准发音并跟着练习。
你也可以查看完整课程“”，更深入地了解相关的语法和词汇。