They are having dinner.
They are wering elegany clothes.
The people are smiling at each other.
They are eating meat and vegetables.
Если "незаперечні речення" отрицательные предложения, тогда так (не знаю украинского) :
Is Mary watching a film? Mary isn't watching a film.
Is Jim repairing his car? Jim is not repairing his car.
Is kangaroo carrying his baby? Kangaroo is not carrying his baby.
Are they dancing? They are not dancing.
Are we playing basketball? We are noit playing basketball.