When; forms questions asking information about specific date.
Empiyan ali?
When will it happen?
Empiyan da?
When was it? or When did it happen?
Empiyan i inmothok mo?
When did you arrive?
Empiyan i impamispis Afo Chiyos cha Paul?
When did God choose Paul?
Empiyan i impangisolat Paul niyay?
Time; forms questions asking about period of time (not a specific date).