“‘Hall.’ The word is ‘Hall.’ Not ‘Har.'” I emphasized to my client, whom I’ll call Emma. She confidently said “Har” back to me. I quickly sketched out a diagram of her mouth and showed her the proper tongue placement to produce “Hall” and said it again for her, clearly showing her my mouth as I did. Emma smiled, focused, and distinctly said, “Har” back to me. I smiled and moved on to the next topic.

If you’re a language learner or teacher, the above encounter is quite normal; it either has happened to you already or it soon will. Learning to speak another language is hard, particularly because you initially hear a new language wrong, but today’s topic isn’t about pronunciation tips. Instead, it’s about why I stopped trying to help Emma’s pronunciation and why you should sometimes stop too.

This statement will be counterintuitive to people who like to “work hard” at learning a language, but a lot of that “hard work” is wasted, and instead, you should spend your time elsewhere. To understand why, we need to learn a bit about Vygotsky’s Zone of Proximal Development (ZPD) and Krashen’s comprehensible input “formula,” i+1.¹

In today’s article, I’m going to briefly explain those bits of theory and research, then tease out some super practical implications this understanding has for your language learning.

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Understanding the ZPD

Vygotsky was a social psychologist and he observed that, if you give someone a task to accomplish, their ability to do it will fall into one of three categories:

• 1: They can do it already
• 2: They can do it with some help (coaching, teaching, modeling, etc.)
• 3: They can’t do it even with help

This makes intuitive sense if you reflect on your own experience:

• 1: If you ask a 2-year-old to walk, they can do it already, so this isn’t learning anything new.
• 2: If you ask a 2-year-old to do a somersault, they can probably do it if you help them (model it, guide them through it, etc.). Thus, learning is possible with your help.
• 3: If you ask a 2-year-old to jump over a 3-foot wall, they won’t be able to do it no matter how much you teach them how to do it.

Or, to make the example a little closer to home for an adult:

• 1: If you ask me to write an article, I can do that already without help.
• 2: If you ask me to write an article without any errors at all, I can do that with some help proofreading.
• 3: If you ask me to write an article on particle physics, I can’t do that no matter how much help you give me.

Vygotsky coined the term “Zone of Proximal Development” (ZPD) to indicate the middle area (#2). Something that you can do with help is in your ZPD, and that’s where actual learning can take place. Tasks in areas #1 or #3 don’t count as learning because things in #1 are things you already know (and thus can’t learn), and things in #3 are impossible for you to do (and thus it’s not learning). The ZPD (#2) is the Goldilocks “just right” zone of learning because you can’t do it by yourself, but you can do it with help.

ZPD is the “just right” zone where learning is possible

• 1: If you can do it already, then it’s too easy, it’s something you already know, and so learning is impossible (because it’s already learned!)
• 2: If you can do it with some help, then it means it’s not too easy nor too hard — it’s just right and learning is possible
• 3: If you can’t do it, even with help, then it’s too hard for you, and learning, again, is impossible.

Understanding i+1

I’ve written about Krashen’s theory of comprehensible input before and it’s quite similar to the ZPD, so only a brief summary of it is needed here. Essentially, Krashen’s theory is broadly what you’d expect if the ZPD is applied to language content:

• 1: If you encounter language that you already know, then it’s comprehensible input, but you’re not learning anything because you already know it. That’s language that is i+0 (input is at your level)
• 2: If you encounter language that is new for you but just above your level so that you can understand it with help, then the language input is i+1 (input just above your level)
• 3: If you encounter language that is new for you and far above your level, then you won’t be able to understand it even with help. That language input is i+2 (or higher!) and it’s not something you can actually learn because it’s too hard

See the similarity with ZPD? With either theory, there is a zone or level that is too easy where learning can’t take place, a zone or level that is too hard where learning can’t take place, and a medium zone where something is not easy but isn’t too hard. It’s just right, and that’s where learning can take place.

Using ZPD and i+1 to supercharge your learning

Okay, enough with the theory. You’re not all nerds like me who enjoy theory. Why does any of this matter for you as a language learner? That’s a great question, I’m so glad you asked it!

1. Don’t try to learn below your ZPD or at i+0

This is a bit of a misnomer because, if you’re below your zone, then you can’t learn if you try—nothing is new, or so little is new that you’re not actually learning。 If something is easy for you, then you’re practicing what you already know, you’re not actually learning something new.

And while practicing what you already know can be good, if you’re below your ZPD, then you’re not even practicing what you’re learning—you’re just practicing what you already know. There’s little benefit to your growth when you’re below your ZPD or at i+0, so try to minimize your time here if your goal is growing. If your goal is just hanging out with locals, awesome, this is a great, easy, comfortable place to be.

If you’re below your ZPD, you’re not learning. You may not even be practicing.

I made this mistake early on in my language learning. Because of how I had jumped around studying through different methods, I had gaps in some quite basic vocabulary. So, instead of spending my growth time at my level, I spent it asking for essentially lists of vocabulary that I “should” know at my level, but didn’t. The result was that, while the content was new to me, it was so easy that I wasn’t really growing.

2. Don’t try to learn above your ZPD or at i+2 (or higher)

Don’t try to learn above your ZPD or at i+2 because you can’t! It’s too hard for you, so you’ll just waste your time trying to grasp content that is beyond your level. If something is truly that hard, skip it and move on. Even if it’s important and not domain-specific, you likely need more background or foundation in something easier before you can understand the content.

The reason for this is that learning is not merely a matter of “trying hard” and then learning; there are stages of learning and immense amounts of development that needs to take place between those stages. Babies have to learn to sit up before they can walk, and learn to walk before they can run. No matter how much you try to help a baby run, they won’t be able to do it if they can’t sit up. It’s developmentally impossible.

The same is true of your language learning, though it’s not as obvious as a baby. You have to learn ostensive vocabulary before you can learn abstract terms. You have to learn basic grammar before you can learn complex grammar. You need to learn general vocabulary before you learn domain-specific vocabulary. You have to understand language at slower speeds before you can understand it at native-to-native speeds. You have to hear new sounds hundreds of times before you can truly hear them and say them just right.

If you try to just “work hard” and brute force your way into something you’re not developmentally ready for, it’ll be as pointless as trying to make a baby run who can’t even stand up yet.

Don’t waste your time on something above your level when you can be learning at your level. Skip it and move on.

I see people making this mistake all the time with pronunciation. They can’t quite pronounce a word right, but they really want to and so they drill, drill, drill, drill, drill a word. I applaud the goal of right pronunciation, but the reality is that you probably need to hear that word and/or sound hundreds of more times until your brain hears it correctly. Instead of endless drilling, you’re better off trying to say it 3-4 times, and if you can’t, just move on.

If content is above your ZPD, you can’t learn it no matter how hard you try.

I made this mistake in my language learning, too, when I was working on listening to native-to-native speech via TV shows. Since I’m interested in history and it’s so crucial for understanding a culture (see: Discovering the Past: How History Shapes Cultural Understanding), I asked my friend to recommend a history TV show, and he did. It was a military historical drama, though, and so filled with tons of domain-specific military terms that were incredibly hard, references to events and people that were entirely new, and content that, overall, was completely useless to my regular life. But, rather than moving on to a new and better topic, I wasted a dozen hours because I wanted to “finish the episode” that was just too hard for me. I would’ve been better off finding something in my ZPD.

3. Learn in your ZPD at i+1

I stated the above negatively—don’t do this—so let me state it positively here: learn in your ZPD at i+1.

This is easier said than done, however, because your ZPD and what is i+1 constantly changes as your level changes. As you progress, you need different amounts of context to understand new language content. A good teacher will recognize small and subtle improvements and adjust their speaking and content to match your level as you progress.² If you’re in a large group of learners, though, even a good teacher can only adapt to you so much when there are 10+ other students around. This is one reason why, if you can afford it and the option exists, I recommend smaller groups of 2-4 students for maximal learning.

Unfortunately, all over the world you’ll find that teachers may not adapt as much to you as you would like. Sometimes this is just poor skill or experience on the teacher’s part and other times the teacher faces a requirement to follow a certain curriculum or textbook. Regardless of why, you’ll need to help your language teacher or helper adapt to your level.

Ways to adjust content to get it in your ZPD and at level i+1

The list below is far from exhaustive, but here are some ways that you can ask your teacher to adjust content, in order to meet you at your ZPD. You’ll have to help your teacher know where your ZPD is, as it changes from moment to moment (and is influenced by things like the affective filter).

I know one person who even created a little chart that had three areas on it “too easy, just right, and too hard.” She placed a pen or marker on the chart during her lesson and moved it around as her teacher taught. It provided a clear, visual, and non-interruptive way for her teacher to know how she was feeling at each moment, all in a way that didn’t feel like “correcting” the teacher, which was important in that honor-shame culture.

You’ll need to help your teacher adjust to your ZPD

Speed

Speed is a major factor that can cause something to be below or above your ZPD. In fact, it’s so consistently a factor that I use one question to assess how well I’m meeting my clients in their ZPD: Would you like me to speak faster or slower? If they want me to speak faster, I’m almost surely below their ZPD but if they want me to slow down, then I’m most likely above their ZPD.

So, if you’re below your ZPD and things are easy, ask your teacher to speak faster. Even content that you’ve mastered will be hard when it’s truly at native-level speed. On the other hand, if you’re above your ZPD, ask your teacher to slow down. Even quite difficult content becomes easier when it’s slow.

Adjusting speed, faster or slower, is one of the simplest and easiest ways a teacher can adjust to your ZPD. The great thing about it is that, no matter what textbook or curriculum a teacher may be using, they can speak faster or slower.³

Vocabulary choice

Native speakers have a good sense of what vocabulary is normal and what vocabulary is uncommon. Ask your teacher to use less common or more common words. “He ventured into arcane regions of the world” means the same thing as “He traveled to unusual places of the world,” but the former is decidedly hard to understand.

BTW, if you or your teacher wonder about what vocabulary is appropriate, this is a wonderful area where ChatGPT can help out in grading words and their relative frequency or difficulty.

References

There’s a large body of knowledge that locals all have (see: Culture Connection: Learning What Everyone Knows). If your lesson is below your ZPD, ask your teacher to include cultural, geographic, political, or historical references that “everyone knows” and it will immediately become harder. If, though, something is above your ZPD, ask your teacher to carefully avoid these things.

Clarity

Another element of speech that your teacher can alter to adjust to your level is their clarity of speech. For example, few people naturally enunciate and speak like a news anchor, but the reason news anchors speak that way is because it is more clear to a broader range of people. By asking your teacher to speak more clearly, you can make things simpler for yourself, or by asking them to speak more naturally, you’ll make the content a bit harder to understand.

Most language teachers or helpers will naturally speak more clearly to you than they would to another native speaker; that can be helpful at the initial stages of language learning, but it can actually hold you back at later stages. This is one reason people may understand their teacher but not understand “normal people” on the street.

Thus, I recommend not asking your teacher to speak more clearly unless you really don’t understand something. It’s better, in general, to ask a teacher to speak less clearly than they’re inclined to speak, since that will help you acclimate to the unclear speech that is normal in your context. You’ll already be at a disadvantage moving from a clear-speaking teacher in a classroom to typical speech, so don’t make it worse by asking your teacher to speak more clearly.

It is a great idea, though, to ask them to speak more naturally in your learning session so that you’re better prepared to engage regular folks on the street.

Grammatical complexity

“The boy sits on a hat. The boy yells at his Mom. His Mom is angry. The Mom yells at the boy. The boy hugs his Mom.” That’s quite simple, grammatically, but it could be much more complex: “While sitting on his hat, the boy yelled at his mother, who got mad and yelled back at him, so the boy hugged his Mom.”

Again, a native speaker will have a general “gut sense” of what is more complex and what is simple grammar. Whatever grammatical complexity looks like in the language you’re learning, ask your teacher to adjust it harder or easier to match your ZPD.

Context

I wrote an entire article on this (see: Context is King: Discovering Language through Life, but another way to make things harder or easier for you is to adjust how much, and what kind of context a teacher gives in order to explain something that is new. The more ostensive the context is, the easier learning will be. E.g. your teacher can help you know “pterodactyl” by showing you a picture of one (ostensive, high context) or by explaining with words what it is (abstract, low context).

Ask your teacher to use more concrete examples if something is too hard for you and to use more abstract examples if things are too easy for you.

Conclusion

Emma’s struggle with pronouncing “Hall” perfectly illustrates the importance of understanding your Zone of Proximal Development (ZPD) and i+1. Despite her determination to improve, the word was just beyond her ability to master at that moment, making it counterproductive to drill endlessly. By recognizing that the task was above her ZPD and shifting our focus to other things, I helped her continue learning in a way that kept her motivated and allowed her brain to process the sound naturally over time. Working within your ZPD ensures that learning remains both effective and enjoyable.

So, the next time something seems hard—whether a sound, a word, a grammatical construction, or even just a vocab flash card—rather than endlessly drilling, step back and assess whether the content is within your ZPD and aligns with i+1 input. If not, adjust speed, vocabulary, context, or grammatical complexity so that it’s within your grasp. Just as Emma will eventually master “Hall” when the timing is right, you’ll find that working within your ZPD ensures consistent progress and builds the confidence to tackle challenges that once seemed insurmountable.

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Footnotes

1. Neither Vygotsky’s ZPD nor Krashen’s i+1 are standalone theories, but rather subcomponents of larger theories they authored. While this article won’t attempt to review either theory, those of you who are nerds like me will want to research Lev Vygotsky’s Theory of Social Development and Stephen Krashen’s Input hypothesis upon which he built his Natural Approach to language acquisition. ↩︎
2. This is one reason why, much to the chagrin of every teacher everywhere, there is no “one method” or “one path” or “one curriculum” for all language learners. Not only does each learner have different needs, goals, and interests, but also each one progresses at a different rate. ↩︎
3. If the curriculum includes recordings of speech that the teacher plays for you, then just ask the teacher to produce that speech himself/herself at the speed that meets your ZPD. ↩︎