1.His favourite writer is William Shakespeare.
His favourite writer is William Shakespeare, isn't he ?
Is his favourite writer William Shakespeare?
Is his favourite writer William Shakespeare or Daniel Defoe?
Who is his favourite writer?
Whose favourite writer is William Shakespeare?
2.They often miss classes, don't they?
Do they often miss classes?
Do they often miss classes or sports trainings ?
What do they miss ?
Who often misses classes?