After living in the UK for a while, I'm well versed in the differences between American English versus what the Brits use. It's brought home to me in spades when I'm in the car during commute time and hear the traffic report. In England, you give way rather than yield when queueing (lining up) to merge onto the ring road (loop around a city). Don't forget to use your indicator (blinker) when you exit the motorway (interstate) or use a flyover (overpass). Travel is done clockwise or anticlockwise rather than referencing the cardinal directions of north, south, east or west. When finding a spot in the car park (parking lot) to do a bit of grocery shopping, don't forget your reusable shopping bags in the boot (trunk) while you get ready to pay and display. Because seriously, parking most places usually isn't free. I always have several one and two pound coins in the glove box of my car to make sure I don't get a parking ticket for forgetting to pay and display the parking receipt for X number of hours/minutes.
However, not too long ago I embarrassed myself because I forgot the Brit meaning for piddle is different from the way I've always used it in the US. Our car service driver, a very jovial and friendly chap, was driving me to the airport and we were chatting. I mentioned that I had rushed to pack my bags the night before because I was piddling around watching TV instead of gathering up my things during the day. Kevin, the driver, got this goofy grin on his face and reminded me that in Britain the word piddle means to urinate. So yeah, that is NOT what I meant at all.