Question

Are you certain that there will be an english speech contest at our school what you response?

Answer 1

Apakah kamu pasti/yakin akan diadakan lomba pidato bahasa inggris di sekolah kita? Apa tanggapanmu?

Answer 2

You are asking about certainty expression.
so, i may respond:
(formal responding)
yes, i'm absolutely sure.
yes, i'm quite sure.
yes, i'm certain.
yes, i'm positive.
(informal responding):
yes, definitely.
yes, certainly.
yes, of course.

if i answer with certainty responding, my response is: i'll try to join the english speech contest to improve my english skills.

if uncertainty expression, i may respond:
no, i'm not absolutely sure.

if i answer with uncertainty reaponding. my response is: because a lot of competition will be done at our school.