"What is a jalopy?"
"Oh, it's an old, beat up car that's practically worthless."
"Oh. We have a word for this. We get it from English. We call it 'sick crab.'"
"Sick crab?"
"Yeah. It's an English word."
"Oh. Hmmm... I guess those are English words, but they don't mean that in English."
"You don't know this English vocabulary?"
"No, I know it, I would just never use it that way."
Meanwhile, in my brain, the following conversation is playing out...

"Why?"
"I don't know. A lot of English words get borrowed and then re-purposed so that they don't quite make sense. Maybe it's like that?"
"That doesn't make any sense."
"It could make some sense. I mean, does it make any more sense than 'buying a lemon?'"
"I guess..."
"I mean, maybe if you sat down to a fine crab dinner and then it turned out the crab you ate was a sick crab, and then you're like, 'Oh man, I ate a sick crab. I'm so sick now!' Maybe it's like that?"
Finally, one of them offers a dictionary that shows the spelling.
"Oh! Scrap!" (The word 'scrap' has only one syllable, but thanks to epenthesis, some ESL learners may insert a vowel to break up the [skr] cluster, resulting in two syllables, or 'sick crab'.)
We all laughed at the misunderstanding, but it made me think about the mindset we need for language learning. Sometimes, when learning a language, we might get frustrated with expressions that make no sense or with grammar rules that aren't consistent or with native speakers whose handwriting is too hard to read or with people speaking too fast. Nevertheless, sometimes we just have to roll with the punches, accept whatever language facts we run across, and just not fight it.
I notice this with children learning their first language--my three-year-old readily accepts almost any new vocabulary I teach him, and then he quickly busies himself with using it in new contexts. Sometimes I hear him using words he must have heard in a movie or in a conversation he was eavesdropping on. There is this kind of appreciation and welcoming of the new and foreign that we often see fade as we get older.
I guess what I'm saying is, sure, it's silly to think of sick crabs and jalopies (or lemons!), but sometimes we just have to run with it if we're learning another language and not get too embarrassed when we get it all wrong.
-Bill