Verified answer

1) They don't go to work on Sunday

When don't they go to work?

They don't go to work on Sunday, do they?

Who doesn't go to work on Sunday?

Don't they go to work on Sunday?

Don't  they or we go to work on Sunday?

2)It is not cold today

3) Ann has already begun to read a new book

Ann has begun to read a new book, hasn't she?

Has Ann  begun to read a new book?

Has Ann or Nick already begun to read a new book?

Who has begun to read a new book?

4) We learn English at school.

We learn English at school, don't we?

Do we learn English at school?

Do we learn English or  French at school?

What language do we learn at school?

5) They will show you how to get there.

They will show you how to get there, won't they?

Will they show you how to get there?

Will they or we show you how to get there?

Who will show you how to get there?

2)It is not cold today
 Is it not cold today? Is it not cold or warm today?

 Is it cold today? Is it  cold or warm today? 

P.S. просто отредактировала, там не надо ставить not - это будет не правильно