1. They are in the street now.
They aren't in the street now.
Are they in the street?
Are they in the street or at home?
Where are they?
Who is in the street?
They're in the street, aren't they?
They're not in the street, are they?
2. She was sad yesterday.
She wasn't sad yesterday.
Was she sad yesterday?
Was she sad or happy yesterday?
When was she sad?
Who was sad yesterday?
She was sad yesterday, wasn't she?
She wasn't sad yesterday, was she?
3. My sister will be at home next week
My sister won't be at home next week.
Will my sister be at home next week?
Will my sister be at home or in another city next week?
Where will my sister be next week?
Who will be at home next week?
My sister will be at home next week, won't she?
My sister won't be at home next week, will she?