Jawaban paling cerdas!
A : are you certain about your still vina's phone ?
B : of course not
A : are you sure he's gonna come to yuda's party?
b : (I'm not sure), let me call him
a : okay
b : anyway do you think the party will be so big?
a : (not so sure) because I asked him this morning and he said he haven't prepared it yet. so I think it maybe somekind of simple party.

*nb : yg dlm kurung itu kalimat uncertainty