She sounds like quite a lot of my Korean teens/tweens. (semi-rant incoming!)

The way my hagwon works is we (foreigners) are hired to teach speaking and writing classes, but they also take reading and grammar classes with Korean teachers and have biweekly vocab and listening tests on a pass/fail basis expecting them to memorize and regurgitate ungodly amounts of crap. It's rare that students will take speaking/writing even half as seriously as the others because that's not what they're tested on in schools. I've had many students who would ace high-level grammar tests, translate complicated reading passages, but couldn't write a basic introductory essay or hold a simple conversation about themselves. They couldn't do much of anything involving actually using the language.

The best part is those with the attitude problems just blame the foreign teachers for their own poor grades in these subjects and treat our classes like many of us did to "bullshit classes" as college students. They're teenagers who spend 12+ hours a day on school/homework, so I don't hold it against them too much, but I resent the parents who express agreement (thankfully, we don't have to deal with parents here directly but we will sometimes have complaints delivered to us by a third person). No, I'm not going to artificially raise little Jun Hyeok's writing grades because he happened to ace that grammar test. He can't fucking write a paragraph. He gets the grade he earns.

The system here is built like this. It saddens me to see the other side of the coin even more: the kids who are fantastic with speaking/writing but struggle with grammar/reading/vocab/listening... aka everything their school tests them on. And they fail. Hard.

I worry about some of them growing up like your student or falling into fragile thoroughbred syndrome.... acing all their tests, dreaming of studying in an English-speaking country, then suffering when they get there and realize after all their years of studying via rote memorization, they can't actually use any of it in any real-life scenario.