B1
S + needn't have + V3 · S + didn't need to + V0
needn't have 和 didn't need to
讲解
两句话听起来很像，意思却完全不同。needn't have V3 表示已经做了，事后才发现没必要。didn't need to V0 表示因为不需要，所以没有做。 常见陷阱：这对表达中文都可以说成“不需要”，学习者容易混用。先问自己：这件事做了吗？做了用 needn't have，没做用 didn't need to。
例句
You needn't have cooked, we ate already.
你根本不用做饭，我们已经吃过了。
I didn't need to buy milk, so I didn't.
我不需要买牛奶，所以没买。
She needn't have worried.
她白担心了。
练习
通过选择题测试你的掌握程度
高效学习“S + needn't have + V3 · S + didn't need to + V0”
语法点“S + needn't have + V3 · S + didn't need to + V0”（needn't have 和 didn't need to）是 CEFR 3 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。