Of all the phrases to learn when heading to a country, "thank you" is perhaps the most important—ranking right up there with the crucial "where is the bathroom, please?" and the informative, "Sorry, I don't speak the language."

In addition to being polite, saying thanks in a foreign tongue shows respect for a local host and an appreciation of another culture. Unlike the caricatures of "ugly" tourists who simply speak louder when they realize they're not being understood, a traveler who at least attempts the language and shows some gratitude for everything from a door held open to change handed across a counter, will always shine in the eyes of locals. Here's what to utter while you're smiling politely:

• Arabic: shukran
• Chinese (Cantonese): do jeh
• Chinese (Mandarin): xie xie
• Czech: dêkuji
• Finnish: kiitos
• French: merci
• German: danke
• Hebrew: toda
• Hindi: sukria
• Italian: grazie
• Japanese: arigato
• Korean: kamsa hamnida
• Norwegian: takk
• Russian: spasibo
• Spanish: gracias
• Swahili: asante
• Swedish: tack
• Turkish: tesekkür ederim
• Vietnamese: kam ouen
• Zulu: ngiyabonga

There are numerous resources online for other languages, including the Etailer's Digest and WikiAnswers.

In addition to saying thank you, there are other ways to express gratitude to local hosts, such as giving presents or sending thank-you notes, and it's imperative to do a bit of homework on local customs to make sure good intentions don't actually result in a cultural faux pas.

For example, when visiting Taiwan, it's customary to give a gift with both hands, and receive it with both hands as well. The host won't usually open the present when you're there unless you ask, and then will be very careful not to rip or crumple the paper. Traditionally, the giver also slightly demeans the gift's value with a phrase like, "It's just a small gift, to show my appreciation," even if it's expensive.

In Japan, gift-giving is a central part of business etiquette, and travelers should bring a range of gifts so that when given a present, they can reciprocate. The best time to give a gift is at the end of a visit, and givers should know that giving four or nine of anything is considered unlucky.

In Saudia Arabia, always give or receive gifts with the right hand only, and think twice before handing over a gift to a casual acquaintance—presents are usually given only to very close friends. When choosing a gift, opt for high quality, but never give gold or silk to men.

Whether saying thank you or expressing it in a gift, some cultural missteps may occur, but remember that sometimes, it really is the thought that counts.