In an English exam, "amn't" is not appropriate (I'd argue that it should be, but that's another day's work).
Amn't is widely used in Ireland and Scotland but it is "regional" usage only. It should not be employed by learners, particularly in formal settings.
Amn't is widely used in Ireland and Scotland but it is "regional" usage only. It should not be employed by learners, particularly in formal settings.