Background: My spouse is German, and tends to misuse some words in English, and also tends to get some idioms a bit garbled. For example, to my spouse, "school" is synonymous with "grade school," and does not include college (but the distortion of this English vocabulary item isn't 100% consistent). So it's hard to know what is meant by, for example, "S. (21yo son) is doing a lot better with understanding underlying concepts [in science] than he was doing when he was in school." This is confusing because S. graduated college in May. Is the improvement since May? Or since graduating high school four years ago? Hard to know! My spouse gets idioms garbled too, but I can't think of an example right now.
Problem: There was a recent question on ELU that reminded me of my spouse's malapropisms, but I hesitated to use this word in a comment to the OP, since it might feel offensive. Is there a softer, but similar, word or phrase I could use instead of saying (after some going around and around with the OPE), "Leave out to dry, used in place of hang out to dry, sounds like a malapropism, pure and simple." (I'd like some help expressing this, whether or not you agree with me about that particular idiom.)
For reference, here's a definition of malapropism, from dictionary.com:
1. an act or habit of misusing words ridiculously, especially by the confusion of words that are similar in sound.
2. an instance of this, as in, “Lead the way and we'll precede.”