"Keep your mouth open please."
Translation:Ağzını açık tut lütfen.
Late reply, but... In accusative case, things can definitely get a little confusing!
- Ağzını = Ağzın ("your mouth") + ı (accusative)
- Ağzını = Ağzı ("his/her mouth") + n (buffer) + ı (accusative)
As you can see, the full word looks identical, despite having different components. Therefore, in the reverse sentence (Turkish to English), Duo should accept either response. :-)