What is Comprehensible Input?

The Comprehension Hypothesis: We acquire language only when we understand messages.

- Stephen Krashen

I came across Stephen Krashen at some point in my adult language-learning life. He popularized[11] something he called comprehensible input. That people—whether young or old—learn languages (and slang, jargon, etc.) by getting messages they understand. I remember the feeling of amazement as I watched one of his speeches. “Yes. Yes. That makes sense!” That was the start of my deep dive into the topic.

On communication

Communication involves transferring ideas from one mind to another. Getting to a sense of shared meaning requires understandable utterances, and that may take some negotiation. There’s a reason the language you use when you are with your peers is likely not the same as when talking to a small child. Differences in vocabulary, difference in concepts understood, these all lead to different ways of getting your point across.

Likewise, if someone tells you something in a language you don’t know, them then proceeding to yell at you in that language is not going to change your understanding. But if instead, they gestured or pointed, maybe demonstrated the task, you’d likely get it. You would start to make associations.

Here’s a memorable demonstration of Krashen’s:

If you don’t know German, after watching the video, do you feel more comfortable with the language and confident in your ability to learn it? I’ve been lucky enough to experience something similar in the language I’m learning, and I dare say it’s even more invigorating when you know some of the words.

What about non-beginners?

Let’s backtrack. In the video, he demonstrated two different ways of communicating—one I would have no hope of understanding and one in which I was able to follow along. His second attempt used drawings and pointing. Does that mean comprehensible input is just for beginners? Well, no. Comprehensible input doesn’t equal gestures or pictures. Going back to the definition, it means delivering a message your recipient can understand. That college lecture? Hopefully the students find it comprehensible. That lawyer making a legal argument? Hopefully the judge finds it comprehensible. That baby crying? Usually not comprehensible, but hopefully someone figures out what’s wrong.

So, yes, when the recipient has a tiny vocabulary, one will use gestures and pictures. As the listener’s base gets larger (more words and concepts are known), message senders will have more to work with. They can then use words that the recipient knows to explain new words.

It's not just one person

Other researchers have conducted studies exploring comprehensible input as well. One is Beniko Mason. She conducts her own research and started the Stories First Foundation, all while continuing to teach. Through her foundation, she promotes her belief that stories are the best way to learn vocabulary[12], and in addition, provides support and resources to teachers that want to teach through stories. Mason teaches English and so I wasn’t able to view it as a language learner, but I was able to follow along with others that use her methods. (You can see examples of her teaching technique below[6a].)

And there’s Karen Lichtman who I’m not as familiar with, but who does research that tests Krashen’s various hypotheses as well as conducts studies related to TPRS-based teaching specifically. TPRS, or Teaching Proficiency through Reading and Storytelling, classes are kind of an inversion of traditional classes. Where traditional classes usually limit the grammar used and don’t restrain vocabulary, TPRS classes typically limit vocabulary words and use grammar without restriction[1]. They are also, as the name might suggest, centered around stories, both oral and written.

Will people understand you?

Now, I’ve talked a lot about the reading[2] and listening side of things, but what about writing and speaking? To go along with the shift of perspective, let’s use the term “comprehensible output” to refer to creating messages others can understand. Comprehensible input feeds comprehensible output. TPRS classes—a boon of comprehensible input for learners—give great insight about what’s possible. Their students’ work has shocked me, and it’s not just a small portion of the students either. One teacher’s chronicles of their students, including some with IEPs (for students with disabilities or special needs), can be found on the blog TPRS Q+A. (Some links below[8].)

So, in short:

  1. If you hear (or see, if signed or written)
  2. And you understand what's being communicated (even if not perfectly or completely)
  3. You'll learn. Brick by brick.

It’s that simple.

Or is it?

Of course, there are opposing voices. As far as I can tell, no one is one hundred percent against comprehensible input. The conflict is over how important it is, what percentage of learning time should be spent on it, and whether or not the learner should find it interesting[3]. While Krashen argues you don’t need anything else[4], many others disagree.

Personally, I’m convinced to spend most of my time using comprehensible input. The biggest problem for me is the lack of options. The language I’m learning (Russian) has a relatively good amount of comprehensible content (although, Spanish is king in that contest 😄), but I want more content and also believe the field can be pushed farther. So here we are.


Digressions, Further Reading/Watching, and Citations

Digressions

  1. A previous version of this essay touched on “advanced grammar.” I found from Chris Stolz of the blog TPRS Q+A, the idea of dividing grammar not between basic/advanced, but between commonly used/less commonly used[9], and it resonates with me. The more common it is, the easier it is to pick up. In English, one example of less used grammar that trips native speakers up is passives. (Here is one study that looks at this: https://doi.org/10.1017/S0142716412000367 )
  2. For growing vocabulary, Krashen is partial to reading whatever one fancies—popular novels, comic books, etc. Perhaps reading is particularly useful because it’s “always on” and you can read at your own pace. You can go over a part again without worrying about wearing out someone’s patience.
  3. Although this might be a conflict happening in education at large.
  4. Please note, Krashen is a linguist, loves grammar, and doesn’t speak out against learning grammar structures if you want to. He’s just saying it’s not essential. Another of his hypotheses proposes that conscious grammar knowledge can be harmful if used in the wrong way.[5]
  5. In another essay, I’ll talk about why some think full-blown grammar lessons are unnecessary and also why they think those same lessons can be harmful when trying to produce language.

Further Reading/Watching

  1. Examples of comprehensible input for learners:
    1. Beniko Mason promotes Story-Listening. Here are some demos (hers are in English): English - The Robber Bridegroom, English - The Wine Well, Italian - The Frog and the Bull, German - Der Suppenkasper, and Spanish - A story
    2. As I said, I’m learning Russian and I believe this is my favorite from In Russian from Afar: Aladdin
    3. Video: What is TPRS? Includes class snippets
  2. A comprehensive article that tackles comprehensible input from a different angle.
  3. A selection from the TPRS Questions and Answers blog:
    1. Beginners, week 7
    2. Beginners, week 8
    3. Beginners, week 11. Includes a student with an IEP, which as mentioned above is for students with disabilities or special needs.
    4. Class with traditional methods vs class with comprehensible input
    5. Second Years’ work
    6. First Years’ work, about 50 hours of input
    7. A third year’s essay
    8. Stats on student work
  4. Where to find comprehensible input for your level:
    • This site has a lot of links to videos and podcasts
    • Many languages have tutors or teachers that offer it in some form. Some terms you use to search are “TPRS,” “story”/“stories,” “comprehensible input,” and “natural method.”
    • And of course, in a short time, right here. Have you signed up to the newsletter? Stay up to date
  5. See various studies (and analysis of studies) from Stephen Krashen, Beniko Mason, and Karen Lichtman

Citations

  1. https://sdkrashen.com/content/articles/2017_who_invented_compehensible_input.pdf
  2. https://www.beniko-mason.net/content/articles/2022-foundations-for-story-listening-some-basics.pdf and https://www.beniko-mason.net/content/articles/2021-is-pre-teaching-vocabulary-necessary.pdf