I've been learning English since I was 7 years old, yet I still have a long way to go in using colloquialisms. Also, schools in Europe teach British English exclusively so most of the times my initial choice of words is British. For instance, I would still use "Autumn" instead of "Fall".
Trevor speaks pretty standard 'merican English, with very few regionalisms so we rarely have any communication problems pertaining to language barriers, although he still laughs at the way I pronounce pomegranate and wreath and I laugh at the way he says fuchsia.
One day, Trevor was tending to the oven in the kitchen while I was doing something else around the house:
Trevor: Do you have a hot pad?
Mickey: No, I don't. (thinking this is what he means by it).
Trevor: Ouch! I burnt myself.
Mickey: Why didn't you use the oven mitts?
Trevor: You just said you didn't have any. (this is what he actually meant)
Mickey: Sorry, lost in translation.
[While we're at it, he spells it ouch! and I spell it auch! so now we actually say ouch with an A, so obviously we're not really in too much pain].