Contoh dialog expressing certainty and uncertainty in english

Certainty:
A: Hey!
B: Hi!
A: How's your english test? How well do you think you did?
B: I'm certain that I did quite well
A: same! I'm sure we'll get high grades

Uncertainty:
A: hello
B: hi
A: I totally flunked my english test. How well do you think you did there?
B: I don't know. I'm really not sure.
A: you are uncertain about how you did there?
B: yes, that's exactly how I feel