1)We’ve all heard well-known stories of ancient mythical creatures.
Have we all heard well-known stories of ancient mythical creatures?
What have we all heard?
Have we all heard well-known stories of ancient mythical creatures or fairy stories?
We’ve all heard well-known stories of ancient mythical creatures, haven't we?
2)Some people believe that Nessie is a dinosaur.
Do some people believe that Nessie is a dinosaur?
Why do some people believe that Nessie is a dinosaur?
Do some people believe that Nessie is a dinosaur or that Nessie is a snake?
Some people belive that Nessie is a dinosaur, don't they?