Well, the Basques do, of course. But they aren’t one of the major ethnicities in these parts; I’ve known only a couple of Basques in the Boston area.
In linguistics courses the Basque language is the standard example of a language isolate—a language that is not related to any other, as far as we know. There are hundreds of other possible examples, but since the Basque homeland is in Spain and France, two of the most “standard” countries in western academia, it’s no surprise that their language would be the canonical example. It’s also the canonical example of an ergative language—more on that below.
Anyhow, what you’re dying to know is what brings up this subject in the first place. The answer is a delicious post in James Harbeck’s wonderful linguistics blog, Sesquiotica, in which he discusses pintxos, the Basque equivalent (more or less) of tapas. Read the post, and then go find a nearby Basque restaurant—or, more likely, a Spanish one—where you can enjoy some pintxos. (But beware autocorrect, which will try to give you beans.)
Now you want a couple of observations about language isolates and ergative languages. Since you’re paying attention, you’ve noticed that I qualified the definition of “isolate” with the phrase “as far as we know.” It’s a bit like going to Skip Gates and he tells you that you aren’t related to anyone else, living or dead, as far he knows. That’s not likely to happen with people, but it can readily happen with languages in which all the related ones are prehistoric. (Of course, because of geography, Basque has borrowed some words from French and Spanish, but that’s not a genetic relationship—more like an in-law.)
So what about ergative languages? What are they? Well, they are languages in which the subject of an intransitive verb has the same form as the object of a transitive verb! Here’s what I mean. First, as you know, English distinguishes subject pronouns (I, thou, she, we, they, etc.) from object pronouns (me, thee, her, us, them, etc.). Also, as you probably know, there are many languages—German, Latin, Greek, Russian, for instance—that do the same for nouns as well. But in all these languages the subject form is identical for both transitive and intransitive verbs: “We are marching to Pretoria” and “We are eating pizza” vs. “They will welcome us.” In contrast, if English were an ergative language like Basque, the first of these examples would be “*Us are marching to Pretoria,” whereas the second and third would remain as stated.