Volapük!

As they say, Ven lärnoy püki votik, vödastok plösenon fikulis.

...and getting back on topic, on flights on obscure Japanese domestic routes (say, FUK-KMQ or ISG-OGN) where I'm the only hairy barbarian around, I've been asked a few times by FAs if I understand Japanese. They always seem very relieved when I say do and thus spare them the ordeal of reciting the litany in a katakana approximation of English