Вам даны несколько утвердительных предложений. Образуйте отрицательные предложения от каждого утвердительного.

1. My mum has opened the window.
My mum hasnt opened the window. 
Has my mum opened the window?
Who has opened the window?
What has mum opened?
Has my mum or dad opened the window?
My mum has opened the window, hasnt she?
2. We have finished the work.
We havent finished the work.
Have we finished the work?
Who has finished the work?
What have we finished?
Have we finished or started the work?
We have finished the work, havent we?
3. Somebody has just left the room.
Nobody has just left the room.
Has anybody just left the room?
Who has just left the room?
Has anybody just left or entered the room?
Somebody has just left the room, havent they?