The weather is going to change by the weekend.
Общий : Is the weather going to change by the weekend?
Альтернативный
Is the weather going to change by the weekend or by next Wednesday?
Разделительный.
The weather is going to change by the weekend, isn't it?
Специальный
When the weather is going to change?
Вопрос к подлежащему
What is going to change by the weekend?
