From the start of the new year, with a couple of breaks, I've been using Duolingo to learn Japanese.
Or rather, currently, it's relearn Japanese.
A long (long) time ago I used to take Japanese night classes, which I enjoyed a lot. It was weird, because I'd spent seven or so years studying French (you get no choice, sooooo...) and somehow I learned more Japanese in a year of night classes than I had in those seven of French.
I've been feeling a little... adrift, I guess? lately, so I figured I'd take it up again. It couldn't be any worse than the disastrous time I tried to learn German on Duolingo, right? (I spent one year studying German at school; again, I had no choice. It and I didn't get along, to put it mildly.)
And no, it isn't. And in some ways it's better, because I've learned a bit more kanji on sight, but currently... yeah, we're on a par. Except for the times I was taught too well and ended up arguing with Duolingo about just how polite you need to be in certain situations (it can be quite rude). And my irritation that some of their language is only what you'd get when stepping into a high-end department store (not joking). And that it doesn't explain the difference between important things — the most fun was hearing "shichiji juunanapun" for 7:17 which is... 七時十七分. You see those two characters that look exactly the same? That's because they are. There are two ways to say seven: shichi and nana. Absolutely none of this is explained in the app; the only reason I know are my night classes, which are thankfully coming back as I study.
The best of it is the Duolingo app itself, which veers wildly between being unnecessarily difficult. Yes, I now know how to say "I am from the UK" and "I am British" but most would just use the latter unless you're being super-specific, in which case the listener will be backing away slowly anyway; I also know two ways to say "my name is ______" and I'm assuming one is informal while the other is formal, but I've only ever learned the formal before and there's no indication the other is informal. I know "watashi no namae wa Pax desu" is more of a mouthful than "Pax toiimasu" but honestly, I'd rather not be rude to total strangers...
The most bizarre thing is the way it's tried to cram this information into my skull. I thought we were doing pretty well, but one update later and you get these gems:
Because I frequently mistake vegetables for a number, you know?
I know very soon now we'll reach the limits of my education and I'll be stuck with their obscure methods of teaching, but I really hope my teacher gave me a good grounding in the subject (enough that a question from a friend had me looking up whether a corpse was 'iru' or 'aru' — to which the answer is apparently both, depending on quite how respectful you are or how ambulatory it is) that it won't matter too much.
I don't recall running into 'zero' at all in my classes. I suspect it's only handy if you're spelling out a number very specifically, but there are a lot of other ways of saying things for that...
Also, fun fact, my teacher was Mr. Hair. 'Hair' in Japanese is 'kami.' 'God' is also 'kami.' My teacher was 'Mr. God.'