S.B.
We went through the same thing with my son, only he was about a year old when he started. And the whining can drive you crazy!! I felt like we tried everything too, we even thought that maybe it was a teething/discomfort issue. After we were confident that wasn't the problem, we just started telling him that we couldn't understand him when he whined, that he needed to use his big boy words. After we started consistently saying that, the phase was pretty short lived...he realized that when he whined we couldn't (or wouldn't) help him. Good luck!!