Translation:This chef often cooks rice from Vietnam.
I wrote, "This chef frequently cooks rice from Vietnam." In English grammar, "frequently" is the correct word. And even though many people don't know and don't use this adverb, mistakenly using "often" in a sentence like this one, at worst, one can say that the two words -- "often" and "frequently" -- are interchangeable. Therefore, Duolingo should have marked my answer as correct. N'est pas?
Youre basically saying a billion people use "often" more frequently than "frequently." What reference do you use.
Whether or not one is used more than the other, both should be accepted. Fighting and putting this guy down because you disagree just makes the devs/contributors/mods less likely to respond when we want a change in the system.