Поставьте предложения в вопросительную и отрицательную форму.
1. It is snowing.
2. We often visit our grandparents.
3. Mary knows many French words.

1. It is snowing.
It is not snowing.
Is it snowing?

2. We often visit our grandparents.
We don't often visit our grandparents.
Do we often visit our grandparents?

3. Mary knows many French words.
Mary doesn't know many French words.
Does Mary know many French words?