Dammit* Duolingo!

They have a “review your words” section and this was in it tonight… Seriously, it wants to teach you “half” as “thirty”. There is one and only one specific context where it means thirty but even then, it’s thirty by context, because half is like an operation or a variable in maths - it could literally be any number (except for when it’s explicitly 0.5 ;)). And the one context when it could be thirty is n時半 - n hour and half an hour - which you could call half past n, or, in English, n:30. But it’s contextual , it’s only thirty because there are 60 minutes in an hour and half of 60 is 30… I’m much more likely to say “half past two” than 2:30**, so 30 for it would never have occurred to me, and certainly not in isolation. It’s awful! If you’re going to make it 30, you need counter units, it’s not 30 in a void, it would need 分, you wouldn’t have a thirty in isolation in Japanese. And then you’re at 〜時三十分, which is a stupid mouthful when you could have just said 〜時半...