辨析did not need to do与needn't have done

Question

急啊啊啊！！！

Answer 1

1.didn't have to 是表示 “过去这件事情没有必要做”,但是实际上可能做了,也可能没做.如：I didn’t need to book a ticket in advance. (= I didn’t book)

I didn’t need to take a taxi from the airport – there was a bus all the way into the city. (= took the bus）
2. needn't have + 过去分词，表示做了不必做的事，译为“其实没必要……”，实际已做过了。表示虚拟语气。如： You needn't have come over yourself。你其实没必要亲自过来。

Answer 2

是这样的.
didn't have to 是表示 过去这件事情没有必要做,但是实际上可能做了,也可能没做.
needn't have done 表示 做了没有必要做的事情.

所以区别说是,前面是可能做,也可能没做. 后面是一定做了.

Answer 3

前一句是说这件事可以做，但是没必要做，所以翻译成（不必做。。。）结果是未做

后一句是做了没必要去做的事情 结果是做了

Answer 4

did not need to do不需要去做(还没做)
needn't have done 没必要做(已经做了)