Question

How does shakespeare's use of the supernatural help create suspense in macbeth

Answer 1

By playing on audience fear

Answer 2

Pretty much what the above user said. Back then, people were actually very superstitious, and took the supernatural and paranormal very seriously. Shakespeare knew this and put supernatural elements in his play to bring another sense of "realism" to them, as their audiences at the time felt that the supernatural were indeed real.

(Source: Intro to Theatre Class)