Impressive work! The idea and the UI is very intuitive.

Though, as a guy who speaks perfect mandarin from Beijing, I’m struggle even to pass the easy ones… So it can definitely used some improvements. The example 你好吃饭了吗 returns hào → hǎo, fān → fàn, le → liǎo. The first two are the model listen my tone mistakenly, and the last one should be le instead of liǎo in this context.

Also I see in the comment section people are worry about tones. I can guarantee tones are not particularly useful and you can communicate with native speakers with all the tones messed up and that’s perfectly fine. Because as soon as you leave Beijing, you’ll find all the tones are shuffled because of every region has their own dialect and accents, which doesn’t stop people from communicate at all. So don’t let tone stuff slow your learning process down.

Please allow me to share some of my views. I'm a native Mandarin speaker.

> I can guarantee that tones are not particularly useful and that you can communicate with native speakers with all the tones messed up, and that's perfectly fine.

Not at all. Tones are extremely important. If you have all the tones messed up, you can hardly communicate in Mandarin. It's true, as you said, that different regions of China have different dialects, and you'll find that people can communicate normally because: 1) The tonal differences in nearby regions are not too significant, and people can still try to understand based on context. And 2) In many cases, people switch to regular Mandarin when their dialects cannot communicate with each other. This is why Mandarin exists. It is an officially regulated dialect that all Chinese people learn, to solve the dialect problem among different regions. Chinese people may speak their own dialects at hometown, but when two Chinese people meet and find that their dialects cannot communicate, they immediately switch to Mandarin. Therefore, the tones in Mandarin are very important. To a considerable extent, Mandarin exists because of tones. You cannot communicate in it with messed up tones.

As a person who lived in Taiwan and reached C1 in Chinese, I can also say that the tones are indeed less important than one might thing once one can say more and communicate more context. In the beginning when you're very limited in your expressive capacity and only can say simple sentences there's less context and getting the tones wrong does produce confusion.

"Because as soon as you leave Beijing, you’ll find all the tones are shuffled because of every region has their own dialect and accents, which doesn’t stop people from communicate at all. "

Isn't this in fact one of the reasons why China relies heavily on the written language because the different regions lose vocal communication ability as the changes in tones and pronounciations render the language understandable to people from other regions?

About the tones not being as useful ... I think there are cases, in which they matter. Take for example 熊猫 and 胸毛: "有 xiongmao 吗？" "Are there Pandas? " or "Do you have chest hair?". Another one: 时间 and 事件. Sometimes it gets comical, but natives can and some will be confused, when your tones are off by too much, and the conversation just started, so that the context is not as narrowed down. Context is key in the language. You can notice that, when you are trying to join a conversation between natives. Until you understand a phrase or most of a phrase, that gives you a hint for the topic they are talking about, you will usually have a hard time understanding anything.

I just tried the tool and it couldn't properly recognize a very clearly pronounced "吃" and instead heard some shi2. I think it needs more training data or something. Or one needs a good mic.

I feel like there is a commonly mentioned idea that "speaking a foreign language is easier after having a drink or two".

I've found that especially true with Mandarin because (I think) a beginner speaker is more likely to speak a little more quickly which allows the listener to essentially ignore the occasional incorrect or slightly mispronounced tone and understand the what theyî're trying to say.

(This is anecdotal, but with n>1. Discussed and observed with other Mandarin language learners)