an interesting/good question again ^_^ normally both of them including same meaning(a room for teaching students=class/classroom) but we use sınıf (not sınıfta) for school(primary/high/university) classrooms, we use dershane for describing a private school offering specialized courses(language courses, prepairing students for academic examination) example: Fem Dershanesi, Kültür Dershanesi (you can search using google) sınıf=class/classroom ex: Okulda yirmi üç sınıf var (there are twenty three classes in the school) sınıfta=in class/classroom Sınıfta otuz altı öğrenci var (There are thirty six student in the class) sınıf has lots of meaning but a main meaning is category/kind example: balık sınıfı, kuş sınıfı, memeli sınıfı... (fish category, bird category, mammal category)

thank you~^^

dershane = clasroom Sınıf = class Sınıfta = at the class

dershane = clasroom Sınıf = class Sınıfta = at the class