Ungkapan kepastian / ketidakpastian dalam pelajaran bahasa inggris

* Ungkapan kepastian

- i'm sure - i'am certain - i can

* Ungkapan ketidakpastian

- I'm not sure - i'm not certain - i can't

Example :

A : Is it difficult to operate this tractor?

B : No, I'm sure you can operate it.