[quelltext]

What's the point of that "lesson"? In English and many other languages politeness in asking for something is achieved by beating around the bush. That's just how it works.

"Could you do me a favor and look into that issue?". Answering yes implies you'll do it. Same goes for the "woulds" and "cans" and "mind doing ... s".

[RHSeeger]

They two different questions. One is asking if you are you able to, the other if you are willing to. I don't teach my daughter to correct people outside the house, but I do want her to speak properly when out there.

It's the same as everyone knows what she means when she says "libary", but I correct her to pronounce it "library".

[taejo]

Pragmatically, neither of them is a question: they are more and less polite requests (or a request and an order). Your daughter is perceptive enough to have worked this out; probably you did too, but at some point decided to override your unconcious competence with concious nitpicking.