Not too bad, thanks!

to not mince matters/one’s words

I do not have the courage to do this.

It’s not my department

not to be exactly an Adonis

He's not my new boyfriend.

not worth a rush

to not pay someone to do something

to not have a clue

It’s not over till the fat lady sings

to not raise a finger

to not say a dickybird

It’s not the end of the world

I’m not afraid to call a spade a spade: he is an impostor

Not to be short of a bob or two

to not see further than the end of one’s nose

I am not well.

not to have the vaguest notion of

to not see the forest /wood for the trees

It’s not what you know, it’s who you know

I'm not going to take that!

to not see the point doing something

Not a bit of it!

It is not nor it cannot come to good.

Do not bother me about that!