Present Continuous
They are playing computer games now. - предложение
They aren't playing computer games now. - отрицание
Are they playing computer games now? - общий вопрос
Who is playing computer games now? - вопрос к подлежащему
What are they doing now? - специальный вопрос
Are they are playing computer games or football now? - альтернативный вопрос
They are playing computer games now, aren't they? - разделительный вопрос
Past Continuous
She was reading a book at 6 yesterday. - предложение
She wasn't reading a book at 6 yesterday. - отрицание
Was she reading a book at 6 yesterday? - общий вопрос
Who was reading a book at 6 yesterday? - вопрос к подлежащему
What was she doing at 6 yesterday? - специальный вопрос
Was she reading a book or a newspaper at 6 yesterday? - альтернативный вопрос
She was reading a book at 6 yesterday, wasn't she? - разделительный вопрос