[mdorazio]

I learned Chinese in college and then lived in China for a year and a half. Personally, I think sentence structure and basic (spoken) vocabulary are the easiest parts of Chinese since there's no real conjugation and particles do all the heavy lifting instead of messing with word forms [1]. The hard parts are memorizing a decent number of hanzi and properly pronouncing with tones. I tried duo to learn some Japanese and found it... not great.

[1] Note: Personally, I find Chinese superior to romance languages in this regard - it was actually really refreshing as a learner.

[daxaxelrod]

I agree, building the mental map of written characters->translation was certainly difficult early on.

Duo is not going to be as good as institutional schooling or immersion but I don't think it has to be to be considered a net positive for all of us. It has lowered the barrier enough to allow people to get started for what is essentially free. I remember 10 years ago I saw rosetta stone cds being sold in barnes and noble for $179+ for just a single level. Sacrificing the time of just 170 SWEs for something like this just seems like a no brainer to me, valuation aside.