"Carrie is a fast translator."

Translation: كَري مُتَرْجِمة سَريعة.

[tsuj1g1r1]

The correct pronunciation is "mutarjima(-tun)" not "mutarjiima(-tun)." :)

[gvarga92]

Can you please explain where the -tun ending is coming from?

[benton.1]

"-un/-tun" is the nominative/subjective case ending that is put on nouns and their adjectives to indicate the subject of the sentence. Case endings are used in MSA but not Arabic dialects. Sometimes Duolingo uses the case endings and sometimes it doesn't.