I was trained British and there are more than a few especially when your outside europe.
But most things you can get away with repeating back how the controller has said it. eg flight level one-zero-zero.
Other things you can get away with doing it the british way and nobody says a thing.
eg read back the things you would in the UK
state limitations first eg after the landing traffic line up and wait. When the controller actually said "line up after the landing"
Its quite funny when you get an ex pat controller and a load of Brits on frequency they very quickly revert back and totally confuse the locals.
And its also been the case that local controllers have said in the pub that they prefer the Brit way of doing things because they can see the advantages. This is usually met with scorn from the FAA background crew.
Saying that I am not that experenced compared to most pilots on here operating in none european climates 4holerpoler for example.
I prefer the brit way but I can see why it causes issues for some pilots if they haven't been here before or only very occasionally outside the mental hours in the London zone.