But certainly

[Xinfu]

'You going to the town? Mind if I stroll along with you?"
"But certainly. I shall be delighted."

The answerer is a Belgian; do you think he uses wrong English here?

[Rusty]

All is regional English and reasonably intelligible to me. I wouldn't consider using the phrasing you highlighted, nor would I say 'shall' in the sentence that follows it, but I cannot call it wrong English.

[Xinfu]

Thank you. But is

-But certainly

the same as

-yes, certainly

?

[Rusty]

I think it is. It could come from the French mais oui ('of course' - literally, 'but yes').

Technically, if someone asks, "Do you mind if ...," the answer should be "No (, I don't mind)," or "Yes (, I do mind)." But a huge number of native American English speakers answer "Sure," "Yes" or "Go ahead."

I don't think the question "Do you mind if ..." has lost its original meaning. It is probably the perception that has changed. We've understood that the poser of the question is simply asking permission to do something and really isn't interested in knowing our thoughts about whether we would be bothered or not. Some people think "Do you mind if" should be replaced with "May I." At least that way, there'd be no question that permission is the topic at hand instead of a query about our comfort with someone's actions.

[Xinfu]

Thank you.