Language students and teachers often look at foreign vocabulary and see how words are made up, what constitutes them, and see how they “make sense”. However, we must keep in mind that native speakers don’t do that, they swallow words whole as “chunks”. Roger Lass refers to them and calls them “opaque chunks”.
His example is the Old English word that has come down to us as “offal”, the parts and leavings of butchered animals. It derives from “off fall”, i.e. the parts that fall off the carcass. That makes sense, but over time we have lost that sense of the word being made up of “off” and “fall”.
But what if the origin were clearer? Wouldn’t that allow native speakers to retain that sense of “falling off” or “having fallen off”? Apparently not, because in Afrikaans, where the word is quite transparent: “avfall”, Afrikaans speakers still don’t make the connection and regard “avfall” as a chunk meaning “the parts and leavings of butchered animals” and don’t think of things falling off at all.
Thus we might take that into consideration when learning/teaching fl vocabulary: while it may help the memory for a vocab test, it is not really the way to ingest the meaning of a word.
(Example from Lass, Roger: Old English: A Linguistic Historical Companion)