Am i prangent?

I remember we used to say “like I could care less” sarcastically back in the late 80s. I moved to a non-English speaking country in ‘89 so I have no idea when “I could care less” shifted from sarcasm to incorrect grammar, but I was surprised the first time I encountered people online mention it as a grammatical pet peeve.

Japan here. We don’t use WhatsApp at all. Line tends to be forced down our throats, though. I’ve so far managed to avoid using it but do get weird looks when people want to communicate over Line and I refuse.