"This is my teacher" - would be better in English
So what's the difference between учитель and вчитель?
No difference. There's something about у/в thing here: https://www.duolingo.com/comment/9012790
Why is the translation "this is my teacher" deemed incorrect?
This is my teacher, should be the write version. Teacher being leaving being "this should be used.
I agree with Andrey ' it is' should be used with objects not people
It. IT. Is it a robot teacher?