07/12/25

I've taught languages for 10 years. Here's what I learned.

1 newsletter, 10 years of learning. Just apply it.


1. Don’t focus on translation. Focus on function.

Not everything can be translated literally.

And it doesn’t have to be.

Instead of asking “what’s the translation of this?”, ask yourself:

How would a native say this in situation X?

Example: “Se me fue la mano” (Spanish expression).

There’s no literal translation in English.

But its function (exaggerating, doing more than necessary) can be expressed with:

I got carried away, I overdid it, I went overboard.

The Brazilian expression “barril dobrado” could be:

A mess, a disaster, or on the positive side: dope, fire, next level.

The tools I recommend to find equivalents with the same function:

  • ChatGPT and Reverso Context

2. Grammar is not for bingeing. It’s for consulting.

A grammar lesson is like a medication leaflet.

You don’t read the whole thing at once.

You look it up when you need it.

Forget binge-watching videos about verb tenses.

You learn how to use all that by seeing it in context.

What to do:

  • Read and listen to real content (videos, podcasts, radio, music) in the language.
  • When you’re unsure about something, look it up immediately.
  • Try to use it.
  • Make mistakes, correct, repeat.

3. A language isn’t a subject. It’s a skill.

A subject is something you study to get a grade.

A skill is something you practice to actually use.

You didn’t learn how to walk by reading about balance.

You didn’t learn how to swim by reading about diving.

You tried, failed, adjusted, and tried again.

With language, it’s exactly the same.

What to do:

  • Include moments of active practice (writing, speaking, repeating) EVERY day.
  • Don’t wait until you feel “ready” to try, just try and adjust along the way.
  • Learn by doing.

4. Fluency is a habit.

It’s not talent.

Or a gift.

Or IQ.

It’s repetition.

You learned English because you were exposed to it every day for YEARS.

Fluency comes from making the language part of your daily life.

So here’s what to do:

  • Listen to podcasts while walking.
  • Write down important vocabulary.
  • Repeat sentences out loud.
  • Use the language in messages with AI or people on apps like HelloTalk or Tandem.
  • And turn it into a daily routine.

5. Good pronunciation doesn’t start in the mouth, but in the ear.

That’s a line from the book How To Learn a Foreign Language by Paul Pimsleur.

You speak English well because you’ve heard it a lot.

That’s how your brain built a catalog of the language’s sounds.

And it was from that catalog that you began to repeat.

With another language, it’s the same process.

What to do:

  • Pick a series, movie, or YouTube channel in your target language.
  • Repeat the lines that catch your attention out loud.
  • Isolate the tricky sounds and repeat them more often.
  • Record yourself speaking and compare.

The more you listen and imitate, the better you’ll speak.


6. Flashcards work, but they’re not mandatory.

Flashcards are just one way of doing spaced repetition.

In case you didn’t know, spaced repetition is a study method that uses increasing intervals to beat your brain’s natural forgetting curve.

But it’s not the only way to do that.

You didn’t use flashcards to learn English, right?

And why is that?

Because when you’re immersed in a language, that repetition happens naturally.

So here’s what to do:

  • If you like flashcards, use Anki.
  • If you don’t, focus on revisiting content naturally.
  • Reread your old texts.
  • Re-listen to podcast episodes.
  • Review with lightness, not with obligation.

7. Anyone who laughs at you for trying to speak another language is doing you a favor.

Seriously.

If someone laughs because you’re trying to grow, that person is an idiot.

They’re doing you the favor of revealing they won’t support your growth journey.

In other words, they’re showing you they don’t deserve a place in your life.

What to do:

  • Keep going, even if you fear being judged.
  • Talk to AI first to build confidence.
  • In extreme cases, cut that person out.

8. It’s not that foreigners speak fast. Everyone does (and you too).

English is fast, but here’s the difference:

You already have a “catalog of sounds” for English, so you understand it without issues.

In another language, that catalog isn’t built yet.

So how do you build it?

Simple: by doing exactly what you did with English.

What to do:

  • Listen to real conversations every day.
  • Focus on recognizing sound patterns that repeat a lot.
  • Practice understanding without subtitles.
  • And above all, be patient. Your ear will adapt, but not overnight!

9. Traditional language courses don’t want you fluent.

A lot of people still believe courses = results.

But what truly matters is what you do outside class.

Courses follow fixed curriculums.

Their main goal is to sell textbooks and monthly payments — not to actually make you fluent.

What to do:

  • Create your own “curriculum” based on what’s relevant to your life right now.
  • Focus on learning how to learn.
  • Spend more time living the language instead of doing “textbook activities.”

10. No one’s coming to save you.

There’s no guru who will magically install the language in your brain.

It’s YOU!

All the methods in the world are useless if YOU don’t take action.

Your brain learns what you repeat with attention and intention.

So here’s what to do:

  • Create a simple plan: listen, repeat, review, and use.
  • Stop waiting for the perfect moment.
  • Start, even if it’s messy.
  • Improve as you go.

And before we wrap this up, one last message:

After reading this, go do something in the language.

Even if it’s just 5 minutes.

Put on a podcast.

Try writing a new sentence.

Practice pronouncing a word.

What you do today becomes fluency tomorrow.

Trust the process.

Go all in, 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.

Discover my language mentoring

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