When I was staffed in Brazil in 2002, I knew about 5 words in Portuguese. This would often confuse taxi drivers, as I would say "Good morning" and "Thank you". They would proceed to speak to me in their native language and then I would look like the confused foreigner.
This was Matthew on Halloween. He couldn't manage saying "trick or treat" or any semblance of it. I considered printing him out some cards I had seen on a special needs website, that convey the message that he can't say "trick or treat" but would like to say it if he could. Instead, I assumed he'd be young enough to get away with not saying it this year. He would walk up to the door, say something totally unintelligible, hold out his bag, and very clearly say "thank you". I think one person was a little confused as to why he wouldn't (she likely didn't realize he couldn't) say 'trick or treat'. He has just enough language to confuse strangers. I remember that feeling all too well.
I really hope that next year I don't need to print out the cards!