A = Are you sure It's going to rain?
B = Yes, I have no doubt that it will rain.
A = Oh, by the way which team do you support in today's match? Real Madrid or Barcelona
B= I am certain that Barca will win.
X ; are you sure it's going to sunny today?
Y: Yes, without doubt
X; Why you so sure with your opinion?
Y: because Today I drank Kulit Manggis