The second chapter of Krashen's book (Krashen, 1982) resonates with my own experience as a language learner and facilitator in multilingual spaces—especially the idea of comprehensible input. To me, it simply means understanding messages in your target language that are slightly beyond your current language level (what he calls i+1). It's not about memorizing grammar rules or drilling vocabulary lists—it's about picking up language when the meaning is clear, although some words or structures may remain unfamiliar.
I've experienced this myself while learning languages. When I was learning Italian, the fastest progress happened when I traveled around Italy. When I talked to locals, I could follow the gist, even if I missed details. Watching news on TV with subtitles, chatting with patient old people who adjusted their speech—those moments stuck because my brain was focused on what was being said, not how it was constructed. In fact, there are many things that are more interesting than grammar to think about during such conversations.
As someone who has facilitated multilingual discussions (but never formally taught), I'd create an ESL classroom that mimics this. Less lecturing, more interaction—think storytelling, debates, or even silly games. As soon as you can make sense of what was being said, try to say something back. That's the magic of comprehensible input: it's not about rules, but about connection.
My classroom would be loud, messy, and full of real talk—because that's how we learn to speak another language.
Krashen, S. D. (1982). Second language acquisition theory. In Principles and practice in second language acquisition (pp. 9-45). Pergamon.