KIGALI, Rwanda—Nelson Mandela famously said, “Talk to a man in a language he understands, that goes to his head. Talk to him in his language, that goes to his heart.” The quote certainly sounds good, but I have spent most of my life in English-speaking countries, and I never really saw the reality of it until the summer.

Now, I see it every day. Rwanda is a place with a pretty substantial number of foreigners, but a white person still stands out almost anywhere. Walking around, especially away from affluent areas, almost everyone stares, curious and awkward. Sometimes they pause to politely greet me in English or French, and then they go back to staring.

But I find that if I respond with even a basic greeting in Kinyarwanda—the national language, spoken by all Rwandans and almost no one else—the tension fades, and they crack a smile. The friendly greeting often turns into a conversation, and occasionally quite a lot more. On several occasions, I have been astounded at the generosity shown to me by complete strangers with extremely limited means. Every instance is different, and I am sure there are many factors involved, but conversations with Rwandans and expats have given me the strong impression that language contributes a lot.

I had never thought of the language I speak being such a critical part of who I am. Kinyarwanda, however, is spoken in so limited an area that its speakers see it as a big part of their shared identity—and the foreigner who makes an effort to learn gets some respect for it.

But then again, being in a place where I hear so little English spoken, I find that talking to Americans is actually kind of liberating. To hear someone speaking in American English, using the accent and colloquialisms that exist nowhere else—it makes me feel comfortable, in a way that is tough to describe. You could say, I guess, that it goes to my heart.