[RHSeeger]

When my daughter asks me "Daddy, can you <something>", I usually reply with "Yes" and then leave it at that. Then should responds with "WILL you <something>", and I do it. I very clearly taught her the difference between can and will by doing so. And now she does the same thing to my wife. And I get in trouble for it. It's great.

[Uehreka]

This sort of thing drove me insane in elementary school and still does to this day. In vernacular English, "can you" is just a more polite and less aggressive form of "will you". Having those two options is really useful. Distinguishing between them like that always feels more like a power play by someone trying to force someone else to use an arbitrary phrasing, rather than an actual lesson in how English works.

[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.

[lisper]

May I humbly suggest training her to say "Will you please ..."?

[RHSeeger]

We actually do teach her to use please. It just wasn't part of what I was talking about. :)