Ethnic jokes are bad, of course, but they communicate something about a culture. They can be clever and revealing if still very bad. They are almost always punching down, though the second one is more punching up (or at least sideways), which is rare.
First, from the UK:
A Spanish man goes to a pub in Wales. He chats with a local. He asks if Welsh has a word equivalent to the word "mañana." The Welsh man, sipping his pint, ponders this question for bit, and says, "no, no word with quite that sense of urgency."
From Spain:
A group of Catalan hikers enter a village in the Basque country. They are thirsty and they come across a fountain in a small village. They ask a man, in Castilian, if the water is safe to drink. The man answers, in Euskera, "no, this water is unsafe to drink." The Catalans respond, "We cannot understand you. Please can you tell us if this water is safe?" The man answers, again, in Euskera, "no, you cannot drink this water." The Catalans say, "This is Spain, speak Spanish!" The man responds, in Castilian, "Yes, the water is perfectly safe."
