Remember how I was musing about learning Russian, Arabic, Chinese, Hindi, or Zulu? It turns out only one of those languages is available on Duolingo, so that made the decision easy: I'm learning Russian.
I was kinda leaning toward Zulu after learning that Black Panther in the new Marvel movies speaks Xhosa, which is mutually intelligible with Zulu. But I expect it'll be hard to find learning resources for Zulu and/or Xhosa, even though they are they two most common first languages in South Africa, together accounting for 40% of the population. Too bad. I was looking forward to learning how to do the click sounds.
By the way, it seems strange to me that Zulu and Xhosa are even considered distinct languages despite being mutually intelligible. I've heard it said that a language is a dialect with an army and a navy (explaining why Serbian and Croatian are considered different languages, or Danish/Norwegian, or Hindi/Urdu), but the Zulu and Xhosa peoples share an army and navy, don't they?
Anyway. So, Russian is fun so far. I thought the alphabet might take a bit of learning, but I soon realized it's almost identical with the classical Greek alphabet I know from mathematics. In fact, I haven't bothered to learn the Russian names of the letters. I keep calling them Pi, Rho, Sigma etc.
There are a few differences. For one, there are two letters corresponding to the Greek Beta, one representing a B sound and one representing a V sound. (I call them Beta and Veta.) Similarly, there are a couple extra letters that are cognate with Sigma (I call them Shigma and Shchigma), and a couple that are cognate with the rare Greek letter San (which isn't used in mathematics because it fell out of use before classical times).
Also, the Russian system of hard/soft vowels means that every Greek-looking vowel (alpha, epsilon, iota, omicron, upsilon) has a corresponding non-Greek-origin vowel that I call "soft alpha", "soft epsilon", etc.
The only really weird part of the alphabet is the letter Ж, which doesn't correspond to any Greek or Latin letter. But even weirder is Ж's position in the alphabet. Whereas all the other non-Greek-origin letters were added to the end of the alphabet, Ж was inserted after epsilon, near the start of the alphabet. What's it doing there? We might never know.
Ancient Greek used to have a letter after epsilon called digamma, but Ж doesn't appear to be related to it. (Nevertheless, I'm going to call Ж digamma.)
The Wikipedia page for Ж notes that it can be used as the logo for the '90s hip hop band Kris Kross. Goddamn there's some crap on Wikipedia.