We need not take the 8 pm (train) to London.
She need not have done it herself.
You need not worry.
You need not be present.
Need we go into all that now?
Need you have mentioned all these figures?
Need you press the skirt? (You need not press the skirt.)
You need not have reminded me about her birthday.
Need you do it all today?
Mother need not have cooked this enormous dinner.