Don’t beat yourself up over this I’m nESL teacher of 18 years. We’ve been taught in educational theory classes not to teach the intricacies of grammar (or maybe we should...?), along with thousands of other strategies Some students do fine wit this, and the grammatical structures come second after mutual intelligibility. Regarding the acronyms, phrases, and such...I’ve hated the phrase “my bad” and have rallied against it for years, but when Webster’s Dictionary releases its new additions each year, and relents to garbage like that (and more recently “irregardless”), you can hardly be blamed for your perceived destroying of the English language. It’s how languages evolve, quite honestly.