In any country in the world, try and speak a few words of the language correctly. It can make all the difference.
Otherwise, the visitor can appear arrogant and ignorant.
A little courtesy can go a long way.
A Chara, Agreed! But there is a big difference between a goodwill gesture in broken language, and rattling off bad high-school French decades later and being surprised when it is met with incomprehension. "They were just pretending not to understand me!" is a common refrain.
When I am in Paris, people usually assume I am Canadian because bien sûr Americans don't speak French, and my accent is weird enough to be mistaken for Québecois.
(foc: Please pay my respects to BillyBob over in Drumcliff for me. I did graduate studies in Anglo-Irish Literature at Trinity ages ago, when the pterodactyls were still roosting in the treetops.)