I've started learning keigo and already having difficulty with it, with the same problem in both そんけいご and けんじょうご. In particular, I'm having trouble understanding the combination of the use of ～ていらっしゃる and お＋verb stem＋になる, and ～ておる and お＋verb stem＋にする.
So what example if you had the question and you wanted to change it so that it involves そんけいご.
Would you change it to: -> 先生はどちらに住んでいらっしゃいますか。 -> 先生はどちらにお住みになっていらっしゃいますか。 -> 先生はどちらにお住みになっていますか。
I've seen a combination of all three usages (e.g. 疲れていらっしゃいます、 お教えになっていらっしゃいます and お教えになっています), but I can't find any clear explanation of when one is preferred over the others. Or are they are equivalent?
Same problem applies to ～ておる and お＋verb stem＋にする, though I'd assume the explanation and reasoning behind it would be the same as そんけいご.