First, Japanese, and now Chinese? This is nothing short of amazing. How did you do it?
Both of these languages have no spaces and an incredibly high volume of characters. To add to this, both have an enormous array of sounds, especially Mandarin, with its tones.
To say I am blown away is an understatement. How did your coders work around these problems?
"To add to this, both have an enormous array of sounds, especially Mandarin, with its tones."
Mandarin is actually pretty average, phonemically speaking- even when taking tones into account. Japanese is on the low end of the scale. German, Dutch and Russian, to name just three, have more phonemes than Mandarin. There are several more.
Let's not even mention Danish, which beats all of these by a large margin. :)
But if you speak to a Mandarin speaker with a flat tone he or she won't understand you, whereas speaking to a Dutch person, he or she are more than likely to understand you.
What about when you factor in the tones for each phoneme? There are 5 tones (flat, rising, scooped, falling, and null*). And not only that, but the phonemes themselves are often morphemes (perk of being a logographic language). That's a lot of information to cram into a single unit. Adding to why I am so impressed.
*May or may not count. It depends on who you ask.
When you factor in the tones for each phoneme which can actually take a tone, the total number of phonemes in Mandarin (+/- one or two, as nobody can agree on certain vowels) is 40-43.
Norwegian has 42, French has 39, German has 45, Hungarian and Hindi have 41, Irish has 44, and Danish, our reigning champion, has 52.
Mandarin is average in terms of its phonemic complexity, in part due to it's low inventory of phonemes. It's only the tones which bring it up to the number it has- without them, it would only be in the low twenties.
Mandarin grammar is simple and the tones are easier to memorise than Vietnamese.. Although Mandarin has an u with the umlaut which changes the position of the vowel and the meaning. for instance: 女人 Nǚrén is woman, while if one were to forget the umlaut and use the wrong tone one could say: 奴人 Nú rén which means slave, so the tones can still present a challenge to some folks. Mandarin also has no word for a/an/the and has no grammatical gender, so while some aspects of the language make it difficult others are quite easy.
This is great I just hope this means they will start working on ways to release it to web as this means four languages that will probably not be available on web for a while.
I know Korean and Japanese aren't available on the website yet, and Chinese won't be first available on the website, but what's the fourth language that will probably not be available on the website for a while?
I thought Hindi would be handled more like Greek, Hebrew, Russian, and Ukrainian...
I don't think Greek, Hebrew, Russian, and Ukrainian will be handled like Greek, Hebrew, Russian, and Ukrainian when the new exercise types finally make it to the web.
There was also a Forbes article where it said half the Duolingo staff worked for 6 months to make Japanese possible. Presumably, it was only so difficult because the platform was too-dependent on characteristics of Western languages at the beginning to make it more easily extensible.
And once you've got it ready for Japanese, I don't think there are too many remaining barriers for Chinese. The Japanese course introduces 100-odd kanji, and the hiragana and katakana. The Chinese course will introduce 600-odd characters, three times as many character forms, but still just an extension of already-developed functionality.