Learn Turkish: Asansör zemin kata iniyor mu? - Is the elevator going down to the ground floor?

In Turkey, buildings use the European floor naming system. The ground floor is called zemin kat (literally "ground floor"). The floor right above it is the first floor (birinci kat). Because of this, you won't use an ordinal number suffix like -inci when talking about the street level!

Why is there an -a on the end of kata?

The verb inmek (to go down, to descend) needs to show where the subject is going. We use the dative case (the "to/towards" suffix) to mark this destination. So kat (floor) gets the suffix -a and becomes kata (to the floor).

I've seen inmek used for buses and trains before. Does it mean "getting off" here?

İnmek literally means "to descend" or "to go down." While it is commonly used for "getting off" a vehicle because you usually step down to get out, in the context of an elevator (asansör), it just means the elevator itself is physically "going down."

Why is the question particle mu instead of mı?

The yes/no question particle follows 4-way vowel harmony based on the vowel right before it. The present continuous suffix -iyor always ends in the letter 'o'. Because 'o' is a rounded vowel, the question particle following it will always be mu!