Why the "Comprehensible Input" Obsession is Holding You Back

[martin_romangette]

Why are people so obsessed with “Comprehensible Input”?

It doesn’t matter if it’s on YouTube, Instagram, Reddit, or specialized forums; people have bought into the CI theory as if it were a magic bullet for language learning. Interestingly, as a native Spanish speaker (and nearly native in Portuguese), I can easily spot the flaws in the level of those who claim to follow this method exclusively. Their output is often poor and riddled with basic errors. Those who actually achieve high proficiency are the ones who supplemented their immersion with active techniques, rather than just “listening and reading” in a vacuum. Don’t get me wrong—immersion is vital, but so are writing, speaking, and the “G-word”: Grammar.

I study grammar actively. The idea that “studying tables is useless” is a tired cliché; the problem isn’t grammar itself, but a lack of a modern, practical approach. Twenty years ago, tools were limited, but today, with AI, we can generate personalized stories to practice specific structures—like a present tense narrative focused on a single verb conjugation. I’ve applied this to my German studies with great success.

In my experience, German is significantly more complex than English. Yet, looking at my two learning paths, I’ve made more progress in German in six months than I did in years of English study. Why? Because I’ve balanced reading and listening with active output and applied grammar.

We also need to take polyglot advice with a grain of salt. It’s easy to claim you speak 20 languages if your only metric is basic comprehension. But how is your output? Can you actually articulate complex thoughts in a professional environment?

Why writing matters: It eliminates spelling mistakes and builds the mental “muscle” needed for speaking. Studies show that writing is one of the most effective ways to retrieve and consolidate information. It’s the perfect “low-pressure” output to start with.

The “Babies Learn This Way” Myth: To be blunt, this is a total fallacy. First, we aren’t babies; our brains are wired differently. Second, it takes children years of 24/7 immersion, constant correction, and eventually, formal linguistics classes in school to master their mother tongue. To think an adult can replicate that process exclusively through passive listening is, quite frankly, absurd.

Listening and reading are essential, but they can’t be done in isolation. If you want to skyrocket your progress, you must incorporate all four skills plus a functional understanding of grammar.

I’m not claiming to hold the ultimate truth, nor am I suggesting that I’m right and everyone else is wrong. However, I do believe we need to critically re-evaluate the narrative that is slowly becoming the ‘common sense’ of the language-learning community. We shouldn’t treat Comprehensible Input as gospel or as an unquestionable dogma. It’s time to weigh the facts against the hype and remember that true proficiency is a four-way street.

[rokkvi]

I am a polyglot. I certainly don’t believe in an input only method. I believe in massive, comprehensible (and if possible interesting) input. I believe in using grammar to fine tune your language and sharpen your skills when you already have some vocabulary and comprehension, but not as a starting point.

I very, very much believe in output as well. Just because you can understand words and sentences does not mean you can find all the words in your own mind when you need them or put them together in the right way to form sentences. That is why nobody really gets that good without speaking/writing. As an example, I had become literate in Dutch already when I noticed I did not know which words to use for “and” and “or” in the language. How could that be? The meaning of these small words was always so obvious to me when I read the language, my mind did not take note of actually remembering these words and adding them to my active vocabulary. Output is where you realize what you are missing, correct yourself, update your vocabulary, get corrections from others and so on. It is essential.

[Obsttorte]

I would second what your are saying. And yes, we have new tools today that can help us learn, although I wouldn’t underestimate the usefulness of good literature. Especially as AI, for example, tends to make mistakes. In the sentences you have posted, which are very elementary, there are a couple of mistakes, for instance.

Ankommen & Aufteilen (this means “arrive and distribute”, which doesn’t make much sense; maybe in a military scenerio )
Wir machen zwei Teams. 🡒 Wir bilden zwei Teams.
Sie stellen die Tore hin. 🡒 Sie stellen die Tore auf.
Wir spielen mit Freunden ruhig. (ruhig doesn’t make any sense here).
die Minuten gehen schnell 🡒 die Minuten vergehen schnell

I’d like to use AI from time to time, too, as it provides some convenience. But it is as if a non-native who is slightly better at the language than you is giving you feedback. It can be correct, it can be.

@martin_romangette

The “Babies Learn This Way” Myth: To be blunt, this is a total fallacy. First, we aren’t babies; our brains are wired differently. Second, it takes children years of 24/7 immersion, constant correction, and eventually, formal linguistics classes in school to master their mother tongue.

Noone ever masters a language, even ones mother tongue. Native speakers make mistakes, too, and some of them quiet a lot and quiet some rudimentary one. Der Dativ ist dem Genitiv sein Tod.

[hiptothehop]

I think one of the challenges in criticizing this popular theory is that people who are really “bought-in” hear this criticism as a denial of the role of CI altogether.

CI as a tool is clearly essential. It is just not the only thing that matters, as was Krashen’s claim.

[devinbrazier1]

Even Steve Kaufmann practices with a tutor and consults grammar books. Balance is key.

[bbbblinq]

““Comprehensible Input” Obsession is Holding You Back.”

No.

[jt23]

I’d like to know who, specifically, is advocating that pure Comprehensible Input without any output or grammar is all that is necessary to learn a language.

Straw man.

[hiptothehop]

I’m glad you haven’t run into those claims, but I don’t think it’s a straw man.

It’s essentially just Krashen’s no-interface position. (i.e. explicit learning and practice don’t contribute to acquisition)

More extreme versions of this such as ALG, and it’s YouTube adapted derivative Dreaming Spanish (Why Grammar Hurts Your Learning) argue that output, explicit study, or even conscious analysis can “harm” long-term acquisition potential. Matt vs Japan Talking ALG

I don’t hold those views, and it is not the prevailing view in the field of SLA research, but the idea is definitely out there.

[sockdoll]

@hiptothehop CI-only seems to be most readily adopted by people who are interested in learning another language but have no idea how to do it on their own, and are looking for an easy path to do so. CI itself is an excellent tool – I’ve benefited from it greatly myself over the years. I agree with Krashen that one can’t simply memorize a language. There is a different kind of learning taking place on the path to fluency, but using CI alone will just limit learning and slow progress.

I’ve always taken a multi-pronged approach to studying any subject that interests me. I’ve been doing this for years, and am currently subscribed to four different language learning sites that I dig into for hours every day. I’m hungry for language learning and won’t limit myself to just one dish on the buffet.

My 2¢

[sockdoll]

@martin_romangette You aren’t the first person to make this argument here, and you won’t be the last. I see very few if any subscribers here actually advocating for a CI-only approach. I certainly don’t. I do see it on other sites sometimes, like Reddit – but those advocates are usually shot down pretty quickly unless you’re visiting /r/DreamingSpanish, or other CI-only subs.

I’m going to go out on a limb and guess that you are reacting to this post made a bit before your own:

Comprehensible Input: A Practical Guide for Language Learners - LingQ Blog

Comprehensible input (CI) is the practice of learning a language by reading and listening to content you can mostly understand. Linguist Stephen Krashen coined the term, arguing that acquisition happens through meaningful exposure, not grammar study. In practice: choose level-appropriate content, engage with it consistently, and gradually push toward more challenging material. The more time you spend with the language, the more naturally it sticks.

If you go to the linked blog post:

Comprehensible Input: A Practical Guide for Language Learners – LingQ Blog

It says in part:

Does CI Mean You Never Need to Speak or Study Grammar?

This is where a lot of people get confused — or frustrated with CI advocates.

The answer is no, CI doesn’t mean you abandon output entirely. What it does mean is that speaking before you’ve absorbed enough input is often frustrating and counterproductive. You don’t have much to draw from. But once you’ve accumulated enough reading and listening, speaking tends to come more naturally — because you’ve heard and read so much of the language that patterns have already formed.

Steve Kaufmann, who speaks over 20 languages and co-founded LingQ, has written and spoken extensively about this. His view: focus on input heavily early on, and speaking takes care of itself once you’ve built the foundation. That doesn’t mean never speaking — it means front-loading input.

Grammar is a similar story. CI and grammar study aren’t opposites. Grammar explanations can help you notice patterns you’re already seeing in your input. Think of grammar as a map and CI as the territory. The map can help you navigate, but you still have to walk the terrain.

Common Mistakes When Using Comprehensible Input

Treating it as entirely passive. Extensive listening during your commute is great. But if that’s your only learning activity, you’ll progress slowly. Active engagement — reading the transcript, looking up words, reviewing vocabulary — accelerates the process significantly.

Avoiding grammar entirely. Some CI enthusiasts overcorrect and dismiss grammar completely. Don’t. A basic understanding of grammatical structure helps you notice what’s happening in your input. It doesn’t need to be the focus, but ignoring it entirely is its own mistake.

---

That blog post also links to this older blog post, which was made by Steve Kaufmann, the co-founder of LingQ:

Comprehensible Input: Definition & Language Learning Tips

In the post Steve points out:

I strongly agree with Stephen Krashen. Massive amounts of comprehensible input is the key to language acquisition. This doesn’t mean that there is no need for output (speaking and writing) or that there’s no value in consulting a grammar guide from time to time. We don’t need to overthink this. We simply need to understand that the bulk of our learning time as language learners should be spent on listening and reading, as this is what will build our vocabulary and sense of intuition with the language.

Having taken the time to read them, I agree with the messages of both blog posts. Comprehensible input has served me very well over the years, as has studying grammar and vocabulary to help me understand what I’m reading and watching/listening to. That in turn helps me with writing and speaking, though those are different skills.

[LeifGoodwin]

I agree with the sentiments expressed in the original post. In my case the CI claims massively impeded my learning of German.

That excerpt from the blog post highlights everything that I think is wrong with the CI approach. It assumes that output means talking, there is no mention of explicit study, and it states that you should be listening early on and the grammar will take care of itself. No, no and no. And I’ll throw in some more no’s too.

My personal experience - I don’t claim to speak for everyone but it matches the linguistic research that I have come across - is that input alone simply does not work. Explicit study is required. This doesn’t mean learning grammar tables, a straw man that Mr Kaufmann sometimes uses. Passive listening is not enough to ensure noticing. This is in part because language has redundancy, in other words, you can understand a sentence without noticing some of the grammar. You also have to do little exercises i.e. constructing sentences and writing them down. That forces you to consider every single element of a phrase. The simplest form is to translate a sentence for which you have the translation to hand. Or use AI to check the output whilst realising that it may make mistakes as noted earlier. Make up new sentences, talk to yourself, that is a form of output. If you have the money to hire a tutor, then that might help, although I think you might be better off with group lessons in the early stages. There is an element of personal preference here, as some of us feel uncomfortable when trying to talk in a language in which we are at an A1 to B1 level. I’ve seen Mr Kaufmann talking with someone when he struggles to make a sentence, and I could not do that.

I will add that I don’t like the way that many CI advocates create a false representation of traditional learning, which they claim is based on rote learning of grammar tables and word lists.

I’ve attended many language classes in my 62 years on this rock, and all of the teachers used the same techniques. Teach something, then get the students to create short, simple passages using the new knowledge, and gently correct if need be. Those exercises reinforce the learning, facilitating memorisation, and highlight any misunderstandings. I have never come across rote learning of grammar.

Unfortunately some people assume that when a professor at a major Californian university presents a theory, it must be true. In truth Krashen’s theory is plain wrong, and positively harmful to the language student, as I discovered for myself.

CI is a great marketing wheeze for input only language apps, as the marketing wonks can claim that their product is ‘based on science’. In truth it is based on discredited science cf phrenology and eugenics.

As an aside, I do wish people would use the term graded input instead of CI, because CI is a term introduced by Stephen Krashen as part of his discredited theory.

[rokkvi]

I will add something. Learning with CI only is not always bad. I will explain why.

1. If your goal was just to be able to read or listen to material. Maybe you are a scholar who is studying texts but don’t really need to be able to speak or write. Maybe you are just really interested in the language even if you don’t necessarily plan to be able to speak it.

2. If you are doing it for periods of time, but will eventually start learning through output as well. Let’s say you don’t have the time, energy or courage to write or speak, then there is nothing wrong with just reading and listening. It’s certainly feasible to learn a language by first becoming fluently literate, then getting to the point where your listening comprehension catches up to your reading comprehension and then finally starting to write and speak and perhaps learning grammar rules to sharpen your output.

Another thing on grammar: Remember how Steve often talks about “Your ability to notice”? (I always hear the phrase in his very voice when this term is used). I have noticed that people’s ability to notice how grammar works is vastly different. Some people seem oblivious to it and keep making the same, silly sounding grammar mistakes for decades, even when constantly corrected. Other people naturally pick up on how to properly say things. The amount of grammar study you need depends a lot on your natural ability to notice. Unfortunately, I think people with a low ability to notice also tend to not be good at learning, understanding, memorizing and using grammar rules in practice.

[LeifGoodwin]

I’m sure people differ in their abilities. I’ve noticed with ice skating that some people pick it up at a phenomenal rate. They tend to have significant experience in other sports such as dance or boxing, and there must be a lot of cross transfer of skills. Some people pick it up very slowly and most at a modest rate. I was very slow for years as I had no sporting history. I wonder if something similar applies to languages? Do musicians learn more quickly? I’ve known people who prefer to talk than listen, and they massacre an L2.

[rokkvi]

I’m slowly but surely writing a book similar to Steve’s book and you just reminded me to get my thoughts in there on which skills and abilities, innate or acquired, translate to being more capable of learning languages. I went and worked on the book instead of writing a lengthy response here.

@LeifGoodwin

I wonder if something similar applies to languages?

[bobivan]

I dislike the term ‘Comprehensible Input’ as it is just a fancy way of stating the bleeding obvious. You need input - Duh! It should be comprehensible - No s**t, Sherlock!

[kraemder]

I think you’re preaching to the choir here. There may be a few input purists but I think everyone here tries to strike a balance of everything.

[Obsttorte]

@kraemder

I think you’re preaching to the choir here. There may be a few input purists but I think everyone here tries to strike a balance of everything.

I’d second that. However, those who are new to language learning can easely get the impression that input is all that is needed. I mean, it essentially turns out to be the plot twist in almost all of Steve Kaufman’s videos and it is a core focus in many other language learning videos. Usually before they advertise you their reader software or short stories book series

@LeifGoodwin

I’m sure people differ in their abilities. I’ve noticed with ice skating that some people pick it up at a phenomenal rate. They tend to have significant experience in other sports such as dance or boxing, and there must be a lot of cross transfer of skills. Some people pick it up very slowly and most at a modest rate. I was very slow for years as I had no sporting history. I wonder if something similar applies to languages? Do musicians learn more quickly? I’ve known people who prefer to talk than listen, and they massacre an L2.

My impression is that despite people have different born with abilities, what is holding them back is a lack of reflection on where they fail and why, and why other persons are actually better. Most people just stick with the “I am untalented but everyone who is good is talented” formula, and if you tell them that this may not be true, they usually refuse to accept this possibility without even bringing up arguments, as it is a comfortable excuse for not achieving your goals.

I am a math teacher working with kids and teenagers. Those who manage to adopt different thinking patterns or change their workflow become rather good, some even excel, and those who do not improve a lot often simple refuse to change their approach.

And talking about musicians. If you talk to them they usually tell you that they practice 6+ hours a day even after playing an instrument for decades. And once they stop doing so, their skills usually decline. David Garrett, a famous german violinist, stated in an interview that he started to learn the violine very early one, 8 years or so, and practiced 6-8 hours a day during his whole childhood (which wasn’t one, then). No wonder he excelled at around 20, considering the amount of time invested. I assume every excellent musician will tell you the same, as will every other artist or people who are really good at something, in general.

I mean, there are people in the forum who state that they are learning languages several hours a day, too. So talented or not, they brute force it with time. And if you look at the varying language level among native speakers, those who are not good at using the language are usually those with a low educational level. They simply don’t challenge their language capabilities and expanding their vocabulary by reading challenging (comprehensible?!) materials or creating complex output by talking about complex matters, and thus stick to a rather low level. I would assume that those who seem to make faster progress in learning foreign languages are usually those who are rather good at their mother tongue, too.

@bobivan

I dislike the term ‘Comprehensible Input’

Me, too. However, the main reason for me is that it is completely unclear what “comprehensible” is intented to mean. It appears obvious for everyone, but everyone most likely interprets it differently. It’s like “honor”. Everyone has an idea what is meant, but everyone has probably a different interpretation of what “honorable” behaviour looks like.

[MarkSiip]

@rokkvi

If your goal was just to be able to read or listen to material.

Don’t forget people have different goals with language studies!

I’m not really interested in speaking or writing the languages I study. I just want to understand podcasts and movies and be able to read books in them.

[rokkvi]

@Obsttorte

My impression is that despite people have different born with abilities, what is holding them back is a lack of reflection on where they fail and why, and why other persons are actually better. Most people just stick with the “I am untalented but everyone who is good is talented” formula, and if you tell them that this may not be true, they usually refuse to accept this possibility without even bringing up arguments, as it is a comfortable excuse for not achieving your goals.

This is so true. Intellectually lazy people often just give up before they even get started and instead of trying to figure out how to solve something, just throw their hands in the air and say it’s too complicated. There is another thing you sort of pointed out, which is how the most successful people tend to be the ones who are both super talented and super hard working. If you’d look at athletes like Michael Jordan or Muhammad Ali, they didn’t just have incredible talent, they also trained like there was no tomorrow. I’m considered very talented with languages (though I’m not exactly considered to be humble) but I’ve also spent an amount of time learning languages that many people find insane. The most talented polyglot I have ever met, the legendary Richard Simcott, puts me to shame both in terms of talent AND the amount of work he’s put into learning languages.

[LeifGoodwin]

I can’t disagree with that although I still wonder if having knowledge or competence in other areas helps language learning. Perhaps attitude is more important.

As regards “I’m no good because I’m not as clever as the others” attitude, the book Mindset by Carol Dweck describes research that backs up your statements. Unfortunately some people develop a fixed mindset, and failures are seen as a confirmation of their innate lack of ability, rather than as challenges to overcome. And perhaps surprisingly, schools can create a fixed mindset. Failure is a natural part of the learning process, rather than a sign of incompetence. That said, we do need appropriate strategies to help guide us, be that hiring a skating coach (essential in my view), or enrolling in a language course. Simply having a positive outlook is not in itself sufficient.

I have in later life learnt to do things that are difficult. I took up ice skating in my fifties, and despite being a slow learner, ten years later I now skate quite well and can do difficult moves such as backwards powerpulls. I know youngsters who learnt such moves in far less time. I am not a natural language learner, but I work hard, and consistently and I am starting to understand films in French. I aim to reach the same level in German. Seeing that I can reach an advanced level of comprehension in French is motivating, despite the fact that German seems impossible. I am sure most novice language learners do not realise how much hard work is required. There is a huge gap between making a video where you conduct a cozy chat with a friend or acquaintance, and being able to function in a range of real world situations e.g. buying DIY supplies for tiling a floor, explaining how to house train a dog and talking with a government tax expert about your tax return. I’m still working on that last one in English, my L1. Responding to sarcasm and condescension is proving, err, taxing.