If I see a language written down, I’m pretty good at figuring out what it is. The writing system, the roots of the words, the syntax … there are lots of little clues if you know where to look.
Hearing a language is different. Sure, I can pick out familiar languages with no problem. French, for all that its pronunciation eludes me, is incredibly easy to identify. Arabic and Chinese are impossible for me to understand at this point but I know exactly what they sound like. But there are so many languages I haven’t really heard before, or at least not very often.
For example, I know that Latvian and Armenian are quite unrelated and could tell them apart on paper, but I find it very hard to identify one or the other in speech. And a clip of Hausa could just as easily be Tibetan to my ear. I feel a bit sheepish about how much trouble I have with those languages.
Think you can do better? Test yourself with the Great Language Game.