He stayed with me for three weeks. I think that should be accepted.
? I used "has stayed" and wouldn't fly
Is it ok to swap "durant" with "pendant" in this case?
They both work here.
"He stayed at mine for three weeks" should definitely be accepted in my opinion. It's slightly colloquial but I think it's the most natural way to translate this sentence, at least in British English.
Surely "my house" is an alternative translation? Pedantry gone a little too far?
Yes, I missed a word ("a ") because it was no there; it happens repeatedly , what is wrong?