What is the difference between anlatmak and açıklamak, both translated as explain?
Similar to the difference to "to explain" and "to clarify." They are very close in meaning and are interchangeable in most cases.
I wrote "Coğrafya öğretmeni konuyu açiklayor" Why is that marked as wrong if anlatmak and açıklamak are interchangeable?
your spelling is incorrect: açıklıyor should be correct
My answer "Coğrafya öğretmeni konuyu açıklıyor" is not accepted. I've reported it.
Why "ogretmeni" not "ogretmen"? "Teacher" is the Subject of the Verb should be "ogretmen", right?
It is a noun compound, which get the 3rd person possessive suffix :) There is no accusative case on "öğretmen" here. :)