what is comprehensible input

Comprehensible Input 101: A Beginner’s Guide

Inside: What is comprehensible input? How do students acquire language?

In Part 1, we talked about proficiency: where we are going in the language classroom. Here in Part 2, I’ll talk about acquisition: how students take language in. If our goal is students who “rise in proficiency” (World Language Classroom), how do they grow? What do they need? What is the best way to get language “in”?

When people find out I teach Spanish, 95% of the time I get a comment like this: Oh man, I took 3 years of Spanish. It’s usually followed by a joke using the few words they remember: Mi casa es su casa. Hah!

Seriously– I get this all the time. From those very informal observations, it seems that we’ve been doing for decades now just isn’t working. When I discovered proficiency-based language teaching, I saw where I wanted to go: I wanted students who could communicate in Spanish, not just perform isolated exercises. And I needed to find a better way to teach them.

With my grammar-based textbook, I had given my students many rules, explanations, and vocabulary lists. We spent a lot of time practicing how to apply the rules, and I gave a lot of vocabulary quizzes to make sure they “knew” their vocab. And yet after all our hard work, my students could barely communicate– especially in an unrehearsed context.

I wasn’t getting the output I wanted. Maybe, just maybe, I wasn’t giving them the input they needed.

Enter comprehensible input.


Basically, comprehensible input is a message that the hearer understands. It’s not a strategy, or a method, but a thing.

All the experts and teachers I follow at least agree on this: comprehensible input– “meaningful interaction in the TL” (Krashen)– is the key to acquisition. It’s the way language gets language into our students’ heads.


Students acquire language through CI. That’s the gist, but there’s a little more.

I can show my students a picture of a giant dog and say “Es un perro grande,” and never come back to the word. That was CI (a message they understood), but that alone doesn’t mean they’ve acquired that language. One exposure usually isn’t enough.

Comprehensible input needs to be compelling, and repeated– in different contexts, at different times, in interesting ways. It’s difficult to pin down the exact recipe, and we can’t control when or what the students will acquire. We can only control the input we give. (Think back to the plant graphic above: we can manage the light, water and air the plant receives– but the growth itself isn’t something in our control.)

If you’d like to study up more on Second Language Acquisition, Bill VanPatten has a good series on this:


The lightbulb finally went off when I realized that I was feeding my students the parts. Bits and pieces: isolated vocabulary and grammar rules. To communicate, they were having to retrieve the words, remember and apply rules, and put it all together. Of course they were frustrated!

It also made sense of my convoluted attempts at immersion. Early on, I’d made valiant attempts at 100% Spanish, scaring my poor students half to death. Input– 100% immersion or not– is only helpful if it is understood. Hearing noise 5 hours a week won’t produce much.

So what did my students need to grow in proficiency?

What they needed was language in context; entire chunks of language. Back on the textbook-free cliff, I just couldn’t grasp how this worked, so perhaps a concrete example will help if you’re there too.

Back in the day, I introduced rules for nouns early on. I presented the rules: adjectives have to agree in gender and number with the noun they modify. We applied these rules to some examples: ____ libro. (Choose el, la, los, las), and practiced, practiced, practiced. Then, we would have a quiz to see who could apply the rule correctly. Supposedly–because they had passed a test on article adjectives– they had “mastered” the concept.

The problem? Well, we’d quickly come across el agua, el problema, etc., and then they’d have to memorize the exceptions. Grammar rules are actually really hard to define, learn, and apply. (I speak Spanish most of the day, and still make mistakes with this.) And here’s the kicker: “knowing” a grammar rule may not even mean it becomes part of your subconscious, internal language construct.

So what can we do?

Now, I skip the explanation, and just define the new terms as they come. Then I work in many, many, examples over the whole year. At the beginning, we’d be creating stories like this: Hay un chico. Es alto y guapo, pero tiene un problema. Es muy desordenado. Su mama visita la casa del chico. Ella dice: “¡Tu casa está muy desordenada!” I can point out that desordenado changes depending on who/what it’s describing. I could ask questions: ¿El chico es desordenado, o ordenado? If I wanted to target the pattern a bit more, I might ask, ¿El chico es desordenado o desordenada?

We could listen to Corazón sin cara by Prince Royce, or do a MovieTalk, too– the key is that the entire time, I am exposing, exposing, exposing them to whole, interesting, complete language. The grammar is becoming instinct, part of their subconscious. One day they will listen to the song or a story, and laugh without realizing they’re listening to Spanish.

Notice that this post is not about total physical response, or storytelling vs. listening, or IPAs. (That is coming next in the series– methods to use that support proficiency.) Those are methods and strategies that apply all the theory we’ve been discussing.

If they are immersed and engaged in compelling, understandable input, they have been given the right conditions to grow.

To be clear, I didn’t entirely abandon all explicit instruction. But I began to differentiate between teaching language, and teaching about it. And whereas I used rely on output activities to “learn language,” I would now say they’re mainly useful to strengthen speaking skills and develop confidence.

If you are still in that place of figuring out how second language acquisition works, these links and videos were really helpful to me. I would really love to hear about any resources that have helped you!

Input vs. Output

Communication vs. Accuracy

Proficiency and Accuracy by World Language Classroom

On Grammar Drills from Musicuentos

Research on Second Language Acquisition

Teaching to Proficiency

What is comprehensible input

Similar Posts


  1. Odile Meister says:

    Thank you for a great article. Just wanted to let you know that the videos from the World Language Classroom site are not playing any more.

  2. Great post and excellent resources to refresh concepts about comprehensible input. Thank you very much. In my case, all videos worked perfectly.

Leave a Reply

Your email address will not be published. Required fields are marked *