Задайте 5 вопросов к предложению.
The cat is silting on the sofa.

Where cat is sitting?
Who is sitting on sofa?
What cat is doing?
Is the cat sitting on sofa?
Is the cat or dog sitting on sofa?

Is the cat sitting on the sofa? Общий
Who is sitting on the sofa? Вопрос к подлежащему
Is the cat or the hamster sitting on the sofa? Альтернативный
Where is the cat sitting? Специальный
The cat is sitting on the sofa,isn’t it? Разделительный