”Doar gătesc pe aragaz” is incorrect?
Jon Abelli it is not correct. I know because I am from Romania
The correct form should be "Eu gătesc DOAR pe aragaz". "Numai" is used for a negative idea. For example it could be:"Eu nu gătesc numai pe aragaz" - "I don't cook only on the kitchen stove". This is a common mistake made even by many Romanians.
It seems that duolingo balives that "pe aragaz" is right and "la aragaz" is wrong.While duoling is right , please keep in mind that people will use the latter with the same meaning as the first.