This past Saturday I had a chat with a Jordanian barista with AMAZING English. He said he'd been in the US for 6 months and had studied the language conversationally in Jordan with other English-speakers for only a few months prior to that. I'm always amazed by people who are adaptive linguists. I am not. Like many things in my life, I can be clunkily adept at something only after a lot of repetition and even then am best when I can do one thing over and over again until it comes "naturally".
Aaaaanyway, my new barista friend was joking about all the painful English idioms he'd encountered that make no sense nor do they follow language rules that are uniformly enforced. Having (briefly) studied his native Arabic, I can see his point.
My favorite of his idiomatic head slappers: We get in and out of a car, but on and off of a bus, train, or airplane. Why?
I have it on good authority that Brits say things like "on" line instead of "in" line for a queue. (Also, they use the word queue.)
I know there are English idiom books and studies out there that would, at length, answer any query I encounter, but it's more fun (for me) to ask you what you think?