"Eat more vegetables, please."
It did that to me the first time around. This is my second go around and I'm up to 9 or so sentences.
Xp farm level?
This seems bugged, I wasnt able to get anymore sentences either.
I am also unable to get anymore sentences, and I've tried several times. I reported it for failing to trigger properly.
The first time I did it, I thought I had broken it, since I got it right on the first try. "Nope, you got this. Moving you ahead!" But I looked back at what we were supposed to learn in the lesson, and not all the new concepts were covered, so I knew it was a glitch. I at least recognize いちばん as #1.
It seems the course is broken if you get this sentence first (either Japanese -> English or English -> Japanese). But when I started the course over and got a different sentence first, it worked properly.
(I have not fully tested this, so it might not hold in all cases! But when the course started with 'いちばんちかいコンビニはどこですか？', everything seemed to work as expected.)
Confession: whenever I'm feeling extra lazy or late I use this lesson too keep my streak up