Not a lot.
I know that although chotomate kudasai is a very polite way to ask somebody to wait a moment, choto-bloody-mate works just as well. And it's faster.
I know that if you can't pronounce do itashimashite, "don't touch my ashtray" will get the message across. And "Monday night" is a fair substitute for mondai nai, which means "no problem".
And I know that if you can't be bothered with the whole rigmarole that follows O genki desuka? You can get away with saying "Pretty genki, thanks."
And I figure that, while yosh is the Japanese word for "OK", yoshi doshi must be close enough for "okey dokey".
And I know that the closest you can get to my name in Nihon-go is Ebanzu, which sounds surprisingly like "Evans". (The final 'u' is silent.)
But of course, I'm only a gai jin so I'm scarcely an authority. >:-/
Of course, that's all written in Romaji. I wouldn't have a clue how to write it in Hiragana or Katakana, much less Kanji.