Every Friends Joke

What is wrong with saying supposably?  Chandler freaks out a fter finding a lot of similarities between himself and a kind of annoying bitter lonely Mr. Heckles, who just passed away. Chandler: What if I never find somebody? Or worse, what if I found her... but I dumped her because she pronounces it, "supposably"? My dictionary translates "supposably" just fine. So it is a correct word to use. What is the problem with it for Chandler then? As commented below, supposedly is an incorrect way to say supposably, something what kids or people of a lower than Chandler class would do.  BUT. My recent googling begs to differ. There is a word supposedly in a dictionary. The trouble is, that both supposably and supposedly are translated as one and the same word to my language. So I went on and dug deeper. And I found that  Americans use  - supposably when they are talking of something they are told to be true, but they are themselves pretty sure IT IS true. - supp...