10/04/25

The (proven) formula to fluency.

(Apply it and thank me later 🤝)

Yes, you read that right. There is such a formula.

And you know what’s crazy?

You already know it, you’re just not aware of it.

If you want to reach passive fluency (able to read and listen) and active fluency (able to write and speak), you need 3 things:

Sound + Writing + Meaning.

In other words, consume content that features:

  1. A native speaker talking;
  2. A transcription of what they’re saying (subtitles, song lyrics, etc.);
  3. The meaning in your mother tongue.

Let me show how to use this formula and become fluent in ANY language you want.

Let’s go.

Why this works: the brain connection

Language learning isn’t magic, it’s neuroscience.

Your brain needs to connect sounds to meaning. That’s the missing link for most learners.

Think about it:

  • If you hear sounds without knowing the meaning, your brain treats them as noise.
  • If you see words written down but never hear them, they remain lifeless symbols.
  • But when you connect sound + writing + meaning, your brain instantly makes a mental map.

That’s why babies learn their first language so quickly: they constantly hear sounds in context, see reactions, and connect everything to meaning.

And that’s exactly what this formula recreates for you, but with modern tools.

Two possible ways to connect the dots:

There are basically two ways for your brain to make the “sound → meaning” connection:

  1. Someone who speaks both languages explains everything to you.

    This works, but it creates dependency. You’re relying on someone else to “feed” you language, which slows you down. It’s like being spoon-fed forever—you never really become independent.

  2. You read what the native is saying while listening.

    This is far more powerful. With subtitles or transcripts, you can use dictionaries, translators, AI tools, and your own curiosity to find the meaning. This way, you’re building the habit of discovery. You stop depending on teachers and start owning your learning.

And today, you have everything at your fingertips: Google Translate, DeepL, ChatGPT, online language forums, and entire communities dedicated to language learning.

Literally no excuses.

The hack: dual subtitles

Here’s where technology makes the formula even stronger.

👉 Install two Chrome extensions: Language Reactor and Trancy.

These allow you to watch YouTube, Netflix, Disney+, or any other platform with two subtitles on at the same time: the original language and your native language.

This is a game changer because:

  • You hear the native sounds.
  • You see the transcription.
  • You immediately understand the meaning.

And I recommend installing both extensions, because if one stops working (sometimes they do), you’ll still have the other ready to go.

This way, you’ll never lose the most powerful tool in your fluency arsenal.

IMPORTANT: Choose the right content (don’t skip this)

Here’s the mistake most learners make:

They try to watch advanced series, news, or podcasts way too early.

Result? They spend hours confused, lost in words, constantly pausing to translate.

This kills motivation, and worse—it wastes time on words they don’t actually need yet!

⚠️ The content you choose has to match your current level.

Here’s my recommendation:

  • Absolute beginners: Start with children’s shows like Peppa Pig or Mickey Mouse Clubhouse. Also, pair this with children’s books. Why? The vocabulary is simple, repetitive, and practical. It builds your foundation fast.
  • Basic to intermediate learners: Move to YouTube channels or podcasts from native teachers who explain slowly and clearly. They break things down just enough for you to follow without drowning in unknown words.
  • Intermediate to advanced learners: Explore native content that you genuinely love—sports, business, fashion, music, gaming, whatever excites you. If you truly care about the topic, your brain will pay attention and absorb faster.

Remember: motivation + level-appropriate content = exponential growth.

How to use the formula: create a system

Here’s exactly how you apply it every day:

  1. Pick your content (level-appropriate!).
  2. Turn on dual subtitles with Language Reactor or Trancy.
  3. Watch and listen carefully.
  4. When you find a new word or structure you don’t know:
    • Write it down immediately.
    • Try to create your own sentence with it right away.
    • Then go to an AI (ideally John AI, my GPT agent optimized for language learning) and ask for corrections, examples and tips.

Why this last step?

Because if you don’t check, you risk memorizing the wrong version, and unlearning bad habits takes 10x longer than learning it right from the start.

This feedback loop is what transforms passive input into active fluency.

Turn it into a daily habit.

Here’s the truth most people don’t want to hear:

Fluency doesn’t come from one big effort.

It comes from small, consistent actions done daily.

Think of it like going to the gym.

  • If you work out once a week, you won’t see results.
  • If you show up every day, even for 20 minutes, your body transforms.

Same with languages.

Watch something every single day.

Multiple times if you can.

Write down new words every day.

Create sentences every day.

Check them with AI every day.

That’s how you build unstoppable momentum.

That’s how you transform yourself.

That’s how you become fluent.

The formula to fluency is not a mystery.

It’s simple:

Sound + Writing + Meaning.

Use it with technology and turn it into a daily habit.

If you do this, fluency stops being a dream and becomes your reality.

And when that day comes, you’ll look back and realize you did it.

You can.

Don’t “believe” it.

Know it.

You’re gonna do it, my friend.

Who is Jonatha Koeller?

I'm a self-taught polyglot, fluent in 6 languages and on my way to the next ones. For 9 years I have been helping people unlock their natural ability to learn languages and achieve fluency in their target language in a matter of months.

I've worked as a language mentor for companies such as Sony Music, Vale, Globo, Accenture, Scrumlaunch, helping everyone from base employees to CEOs.

I don't know what you'll find more surprising: that I did all of this, or that I'm bald at 26. Either way, you can be the next person I’ll help become fluent by unlocking your natural ability to learn languages.

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Have private lessons with a native tutor every week and speak English fluently in 6 months without needing grammar books and boring exercises.