My most common trouble is "phrases" or sayings in local regions or areas. It can give me different/conflicting information when I try to understand it.
I end up memorizing them.
Idioms. This is the hardest part about learning English, period, and the number one reason it's actually a relatively complicated language. The reason English has so many idioms is that it's such a culturally rich language; it's spoken over such a geographically large area and has thus picked up different ways of expression from literally everywhere.
I was an English major before I turned to law enforcement. I'm Swedish, but our educational system is top-notch and, more importantly, English is everywhere in our culture and media. We don't dub stuff, unlike a large part of Europe (Germany, France, Spain, Italy), which means we start learning English the moment we start listening to radio, TV, or start reading ads, commercials, news, etc. in the cities. That's how you teach a language to a people; let it permeate society.
I'm schooled in British English but have more experience with American English since most online people are Americans. Either way, my vast knowledge is always at anyone's disposal.
