Как написать эти предложения отрицательно. i am a shop assistant. den is from germany. it is a wall. our sisters are doctors. за ранее

I am not a shop assistant. Den is not from Germany. It is not a wall. Our sisters are not doctors.

I am a shop assistant. I am not shop assistant.
Den is from Germany. Den is not from Germany (Можно сокращенно, Den isn't from Germany)
It is a wall. It isn't a wall.
Our sisters are doctors. Our sister's aren't doctors.

Удачи))