If you plan on doing some language learning before you volunteer, all the more power to you. For those cases where you can only make basic progress, Andrew Wahba of the True Travellers Society had a great tip:

“I like to go with a ridiculous question or something not particularly important like ‘do you have hot oven bread?’ or ‘I like turkey sandwiches.’ I like to learn something that makes them shake their head, laugh and ask “why do you know that?”, which of course I never understand because they ask in their language.””

A couple of great phrases I’ve learned:

• Chakkas! “Great”, in Bihari (from Bihar, India) slang. Learned it from a staff member while volunteering in another region in India, and impressed an American co-worker in Chicago who was born in Bihar with it much later. Unfortunately I was never in Bihar, and had the opportunity to use this word only in Hindi-speaking parts of India,where it was only sometimes understood.
  
• Gdje si kuca stara? Out of date slang, equivalent to “What’s shakin’, Daddio” or something, in Bosnian. Literally: where are you old house?
• Ta piro sto craneo. “I was so angry” in Greek. Literally: I took them by the skulls.
• Segitseg. Hungarian response to “How are you” meaning “SOS”, i.e. terrible.
• Dva krat meraj, raz rez. “Measure twice, cut once.” In Slovak.
• “I like it hot and spicy” in Thai. I don’t actually know this, but saw it underlined in a Thai phrase book and found it memorable. I’m not sure exactly what the equivalent sounds like in Thai, but it could be pretty funny, and possibly multi-use.

These don’t really have particularly practical applications – as Andrew pointed out, it is more to make people smile.

I concur 100% that humor is a great way to make a basic connection. I also think it is great because you can convey (at least to some extent) not only that you are making an effort to communicate in the local language, but also that the balance isn’t always tipped so that you as the volunteer have something to give and they have something to gain. When it comes to their language, they have something to offer you because they know more than you.

What crowd-pleasers have you learned?