British English has some great insults but you won't hear anyone calling someone a twonk or a knobhead outside of our isles because apparently British insults haven't made that leap outside of our borders yet.
The UK’s communications regulator, Ofcom, took a poll of the most offensive swearwords in the British language and a bunch of foreigners have made a list of the ones that most other people don't understand.
Yes, the following will contain lots of swearing.
On the plus side you could get away with calling someone from elsewhere a twat, tosspot or a bellend and not offend them or at least they wouldn't realise that you are insulting them.
The top 10 insults you can safely direct at non-Brits are:
6 Couldn't organize a piss up in a brewery
8 Wank stain
10 Silly sausage
12 Face like a slapped arse
13 All fur coat and no trousers
So if you ever come across a Twonk Cockwomble who couldn't organise a piss up in a brewery and had a face liked a slapped arse, feel free to let them know if they are not a Brit.