I feel the Turkish course is too forgiving regarding typos
For example the suffixes "-da" and "-dan" shouldn't be acceptable when it is "-de" and "-den" .
I agree with Selcen, and also, remember that Duolingo is a computer program. It doesn't know what you're thinking, and can't always distinguish between typos and real mistakes. (This is true in all of the languages, not just Turkish.) It would be very frustrating if it didn't allow for typos, though, so I really like that it makes the effort.
i think you are right. for example in a french course a mistake between du, des or de would not be forgiven. let's say it happens because turkish words are long and these endings are at the end of the words so the system might recoginize them as typo, however the system doesn't accept different conjugations or plural endings either in other courses like spanish and french.
in spanish course it even shows error messages like 'You used the plural "padres" here, instead of the singular "padre".' maybe it can be adjusted but i don't really know how the system works.
we don't accept different endings or conjugations. A typo that creates another meaningful word is not forgiven (Evden instead of evde OR evim instead of evin).
However evdan instead of evden is forgiven, it is not meaningful, the user made a typo or missed the vowel harmony. But they'll see the typo message so they should understand that it was not correct. I think it is OK to be lenient and anyway programming this would probably be too complicated (and nothing we can do, developers do that)
and only 1 typo per sentence is forgiven
i actually guessed that it doesn't forgive when the error is also meaningful word but i misunderstood the problem. i thought it doesn't show error when you write -den instead of -de and vice versa. i completely ignored vowel harmony, you are definitely right. i can estimate how tricky this is for developers. hopefully when hungarian comes out the team will reevaluate this problem and bring a solution. (maybe it's better this way as you said i'm not sure)