I would much rather that I be about Idiom, but then I'd have to pull out a bunch of books and run by favourite examples. That's the hardest part of learning a foreign language - not the irregular verbs, but the idioms. The majority of them do not translate well, that is, the meanings of the words are too practical and do not translate to the meaning of the idiom = the sum total of the separate parts.
When I get involved in an explanation like this, I arm reminded of a lesson for writers. I think this is apocryphal but it's fun. I never saw it on any course but I did hear of one result of the question: "Without using your hands, describe an accordion." My counter question would be "Without using your hands, explain how to fold a fitted sheet." The result, perhaps a myth, is that one wannabe writer got so good at descriptions of this nature that he ended up writing instructions on packages.. Ah, the romance of merchandise!
We've used up our spare parts in the service of effective description.