Need not and need not have

Need not and need not have

· That car is not broken. You need not fix it. (You have been told the car does not need fixing, as it is not necessary)

· Why was the car fixed? It wasn’t broken. You need not have fixed it. (Although the car was fixed, it was not necessary. You were not told that information before you fixed it, even though it was important to know.)

Did not need to (do) and need not have (done)

Did not need to means it is not necessary or important to do and you knew that information at that time.

· I did not need to get up early today, because I did my homework last night.

Need not have done means a task was done because you did not know what would happen or if you would finish it sooner than planned.

I woke up early because I needed to finish my homework or I would be late for school. However I finished it sooner than I thought, which meant I need not have got up that early.