I remember seing this episode a few years ago - even more than once I think. It was about an old man, who was sure that he was able to understand pokemon and be able to talk to them in their language.
To me the whole talking to and understanding pokemon thing is kind of confusing. In some episodes it seems like every pokemon is able to understand human language perfectly (like in episode 1 where Pikachu obviously reacted to what the people around it said about it), in others it seems like they do not (even on a Pokemon TCG card of Lucario it is stated that THIS pokemon is able to understand the human language (but not the others?)). In some episodes it seems like humans can understand pokemon (it once was said that a trainer can understand his/her pokemon if he/she knows them well enough - and it was shown with Ash and Pikachu a lot of times), in others humans can't understand their Pokemon (like in this one, where Ash needs a translator to understand his Pikachu o.o).
I guess the writers are kind of undecided about this matter.