"I am not playing, but I am working."
Translation:Nem játszom, hanem dolgozom.
Nativ speaker: You are right. In colloquial Hu langue many people use it as you remarked, so both version is normal (in this case) - althouh the DL version is the "official" one. Please, note that Hu language has a subject AND an object verb conjugation. E. g.: Én írok egy levelet (I write a letter), Én írom a levelet (I write the letter). So, in the last case the emphasis is on the object. In the DL example sentence the two verbs are seldom used together with an object, so it is not strange when you use any of the two conjugation forms.