I've occasionally heard (and sometimes used) "five and twenty to six". But that is now rather archaic.
I think you're more likely to hear (in conversation) "twenty five to six" rather than "five thirty five", and even more likely just to get "twenty five to" with the hour being implicit.
As for half hours, in UK English, half hours are always past the hour, so "half six" would be 6:30. When asking the time, I'd expect to hear "half six" or "half past", few would say the full "half past six", or "six thirty".
One of the few things I remember from German lessons is that half hours are the opposite way around in German. "Halb sechs" isn't 6:30 but 5:30.
|