Why You Can Understand but Still Can't Speak

"I understand everything, but I can't speak."

If I had gotten a euro for every time a student told me this during my twenty years of teaching, I could have funded a research lab on language learning.

Speaking is a burning concern for many language learners.

And it's understandable. After all, we learn languages mainly to communicate effectively in any situation. We want to speak clearly and fluently, not just read and listen.

As a language learner, I understand your pain because I have also struggled with speaking while learning six foreign languages.

As a scientist, I know that it happens for a reason.

I will show you:

• Why speaking is the most complex skill to build
• Why you can understand better than speak
• How your brain turns ideas into words
• How to manage speech anxiety
• How to build automaticity and fluency with some powerful strategies

1. Why Speaking Feels So Much Harder

Speaking is not a simple act of opening your mouth and letting the words out.

That's how we imagine it, but it is far more complex than you think.

When you speak, your brain orchestrates multiple cognitive processes in milliseconds and sends instructions to your articulatory muscles (vocal cords, tongue, lips, and jaw).

In a single moment, you have to combine your knowledge of language components and discourse, skills, and communication strategies simultaneously.

You need to make adjustments in the register (formal vs. informal), depending on your audience, and have a clear communicative goal. Is it a casual conversation with a friend or a business meeting with a partner?

Knowledge of language and discourse includes specific features of language, such as:

• pronunciation (sounds, stress patterns, rhythmic structures, and intonation)
• grammar
• vocabulary
• discourse (understanding how to structure your message clearly and appropriately)

Core skills are your ability to process speech quickly, manage the flow of speech, and negotiate with others.

Communication strategies (cognitive, metacognitive, and interactive) are needed to:

• Make yourself clear
• compensate for limitations in knowledge of language
• think consciously and plan your message in advance
• check for listener understanding and rephrase
• use gestures and body language
• evaluate the audience for their background knowledge of the subject, social status, and interests
• check if communication is going in the right direction and adjust the course if needed

Writing about these operations has already made me tired. Just imagine the scope and the speed of processing that your brain does in milliseconds! It is mind-blowing.

In your native language, all these things happen almost automatically, without much of your conscious effort. You have performed these operations millions of times. That's why they feel effortless and run pretty much on autopilot.

Speaking in a target language is far more complex and more cognitively demanding, because these processes and skills are still learning to work together. They are slower and less automatic.

For this reason, if you want to speak fluently, your main goal is to develop automaticity. I will tell you how in the strategy section.

Stay with me a bit longer to deepen your understanding of the speech process.

2. Why Understanding a Language Isn't the Same as Speaking It

Understanding and producing language overlap, but they are different:

• They activate two different brain regions linked to speech — Wernicke's area and Broca's area.

Wernicker's area has motor neurons involved in the comprehension of speech. It is located in the temporal lobe regions.

Broca's area is responsible for speech production and articulation. It is located in the left frontal lobe.

• Understanding (listening or reading comprehension) relies on recognition, while speaking is a constructive process.

Listening involves rapid decoding. While the other person speaks, you match their words to patterns in your brain almost instantly.

Speaking is a construction under enormous time pressure. You have to build the message yourself while the clock is ticking.

That's why listening feels easier than speaking.

When you listen, you are "riding downhill" because the momentum comes from the speaker. When you speak, you generate the force yourself, so it feels like going uphill.

3. From Thought to Speech: How Your Brain Turns Ideas into Words

Levelt's (1989) model is perhaps the best for representing the stages of speech production. It is quite complex, but I will simplify it.

Basically, it involves three independent systems:

1. Conceptualizer
2. Formulator
3. Articulator

Conceptualizer

First, you must decide what you want to express in words or form a preverbal message. At this stage, the message exists in a representation other than language. Here, you employ your knowledge of the world, situation knowledge, and the rules of discourse.

Formulator

After the conceptualizer, the preverbal message arrives in the formulator. The formulator creates a phonetic plan ready to be articulated.

Here, three main things happen to the message:

1. Content words are selected from the lexicon (lexicalization)

2. The message is given a surface form, i.e., morphemes are attached to words, and functional words are inserted to create a grammatically encoded message (grammatical encoding)

3. The message is phonologically encoded (phonological encoding).

These three parts are autonomous and work independently of each other.

Articulator

The articulator converts the phonetic plan into muscle movements for the articulators (tongue, lips, larynx, etc).

This is the speech that a listener will hear coming out of the mouth of the speaker.

Next, you get feedback about your utterance.

One is internal feedback, the other is external.

In internal feedback, the speaker can monitor the utterance before it is actually articulated. It means that before articulation, the speaker can edit and correct their speech to avoid or minimize errors. If this were always the case, the listener would never hear any error. But experience shows that some errors do get out and become quite obvious to the listener.

In this case, we can monitor what we produce via the external feedback (overt speech). When this happens, the speaker may hesitate briefly and then replace the erroneous part with the correct form before moving on. This hesitation and repair is a normal part of speech.

In your native language, this whole process happens lightning-fast (600–800 milliseconds per word). In a second language, it's often slower because retrieval is less automatic and monitoring is heavier (Indefrey & Levelt, 2004; Indefrey, 2011).

4. Passive Knowledge Doesn't Automatically Become Active

Many learners have large passive vocabularies. They recognize words but can't retrieve them quickly.

The brain is efficient.

If you never use certain words in speech, it doesn't strengthen the retrieval pathways needed for fast recall (Nation, 2013).

Passive vocabulary is like a closet full of clothes you never wear. You recognize each shirt when you see it (listening), but if someone says, "Quick, dress for a wedding, you've got 30 seconds!" (speaking), you panic and can't grab the right outfit fast enough.

In language learning, you might understand desarrollo sostenible (sustainable development) on a podcast. Still, when you try to use it in conversation, your brain searches frantically and comes up empty or too late.

Without retrieval practice, the path from meaning to word to speech stays overgrown.

5. Input Without Output: The Tennis Match You Only Watch

If your study routine is 90% listening and reading, you're a language consumer.

You've built a database but never learned to query it in real time.

It's like watching Wimbledon for years but never holding a racket. The first time you play, your body doesn't know how to hit the ball, even if your mind knows the theory.

In speaking, your "muscles" are the neural and motor patterns for producing language. They grow only through use.

Decades of SLA research show that output is not optional if you want to speak fluently.

Producing language activates processes that comprehension alone can't:

• Noticing gaps (realizing what you can't say).
• Lexical retrieval (finding the right words under pressure).
• Hypothesis testing (trying a form and adjusting based on feedback).
• Proceduralization (turning slow, conscious recall into fast, automatic use).

This is the shift from declarative knowledge (knowing about the language) to procedural knowledge (being able to use it), and it's what we call automaticity — the ability to retrieve and produce language quickly and accurately without conscious thought (DeKeyser, 2007).

Without that push to speak, your knowledge remains passive (Nation, 2013; Swain, 2005).

6. How Language Anxiety Puts the Brakes on Fluency

In my classes, I've seen brilliant students staying silent because they're terrified of sounding foolish.

Anxiety is a serious problem.

It is understood as a feeling of tension and worry connected with speaking in a foreign language in front of others (Horwitz and Young, 1991).

Language anxiety can paralyze you both emotionally, physically, and neurologically, because it activates the amygdala, hijacking attention and shrinking working memory (Eysenck et al., 2007; Botes et al., 2020).

Anxiety may also surface as nervousness, excessive laughter, or even muscle tension leading to headaches.

What commonly causes anxiety is the feeling of inadequacy in expressing their ideas in a new language, the fear of making mistakes, and the fear of negative social evaluation (Horwitz, Horwitz, and Cope, 1986).

Many learners acknowledge that speaking is the most stressful aspect of learning a foreign language.

The feeling may be intensified by your personality traits, previous experience, negative convictions about their abilities, especially constant comparisons with other students, and the level of difficulty of foreign language tasks.

What happens as a result?

Avoidance.

You avoid participating in communicative activities.

You avoid meeting other people to practice speaking.

You stay silent.

You choose to listen.

When you finally decide to speak, a voice shouts in your ear, "Don't mess up!" You start becoming even more self-aware and locked down. You panic.

Quite naturally, you get limited practice and block the development of your speaking skills.

It is not easy to get over anxiety, but some strategies might be a good start.

Anxiety-Aware Speaking

• Speak for 90 seconds to a partner who agrees not to interrupt or correct you.
• Afterward, receive only 2–3 focused feedback points (one useful chunk, one grammar fix, one pronunciation note).
• Gradually add background noise, a short time limit, or a moving conversation.
• Search for opportunities to practice in public, but start small, no big speeches. Start by talking about familiar things with people who make you feel safe.
• Slowly move on to more difficult conversations. Mastering small tasks makes you feel more capable and confident.
• Be kind to yourself.
• Seek help in the case of severe anxiety.
• Practice makes perfect. It is obvious. So do it regularly.

7. How to Automatize Language and Speak Without Thinking?

The fastest way to build automaticity is through deliberate fluency practice, which focuses on repeated production with increasing speed/complexity and targeted feedback (Skehan, 2021).

It is simple at its core.

You need repetition and sustained practice over time.

Expose yourself to speaking in a variety of communicative situations with different partners. Push yourself to produce language from day one, even if you lack solid vocabulary and complex grammar.

Make sure your practice is non-mechanical, but natural, rich, and varied.

Instead of relying on listening and reading, which give you comfort and a sense of accomplishment, prioritize speaking. It will speed up cognitive processes in your brain and improve the coordination of language components and skills.

With sufficient practice, you will learn to adjust language, context, audience, and purpose in a split second. Speaking will feel easier and more natural.

Now, the question is how to practice?

There are many strategies. It is impossible to list all of them in this limited space, but let me share with you a few powerful ones that I recommend to my students to speed up their progress.

Strategies for Building Automaticity and Fluency

4–3–2 Fluency Sprint

• Tell a short story three times: first in 4 minutes, then 3, then 2.
• Keep the meaning the same, but speak faster each round.
• For example: El fin de semana fui a la playa con mis amigos y… (This weekend I went to the beach with my friends and…).
• On the final round, have your partner interrupt with quick questions ("Why?" / "How exactly?") so you adapt under pressure.

This keeps your message stable while forcing the Formulator and Articulator to speed up.

Output-First Cycles

Convert passive knowledge into active use.

1. Before input: Speak for 90–120 seconds on a topic.
2. Input: Read or listen on the same topic (3–5 minutes).
3. After input: Speak again, this time using 3–5 new words or structures you noticed.
4. Speed retell: Compress your speech into 60 seconds.

Some prompt ideas in Spanish:

• Compara dos ciudades y elige una para vivir. (Compare two cities and choose one to live in.)
• Explica cómo los hábitos superan la motivación en el aprendizaje de idiomas. (Explain how habits beat motivation in language learning.)

This forces your brain to retrieve, then enrich, then retrieve again, locking words into active memory.

90 → 60 → 45 Compression

Expand your planning window with speed drills.

• Speak on a topic for 90 seconds, then repeat it in 60 seconds, then in 45 seconds.
• Keep all the core meaning while shortening the time.
• This forces you to pre-plan more content before you start speaking.

Over time, you'll begin preparing multiple sentences ahead, not just the one you're saying.

The Retrieval Grid

Give yourself retrieval "rackets" to swing every week.

• Make a 3×3 grid for a topic.
• Row 1: nouns/chunks (una fecha límite — a deadline, un ascenso — a promotion)
• Row 2: verbs (delegar — to delegate, negociar — to negotiate)
• Row 3: sentence frames (En mi experiencia… — In my experience…, Lo que me preocupa es… — What concerns me is…)
• Roll a die to pick cells at random and make sentences within 3 seconds.
• End with a 60-second mini-talk using at least 6 items.

This combines pushed output with timed retrieval — precisely the conditions research identifies as essential for moving from knowledge to automatic fluency (Swain, 2005; Skehan, 2021; Tavakoli & Wright, 2020).

Final Thoughts

If you understand but can't speak, your system is unbalanced. Comprehension and production are separate machines, and one of yours has been undertrained.

The fix is targeted practice:

• Speed sprints to close the timing gap
• Output-first cycles to activate vocabulary
• Anxiety-aware drills to tame over-monitoring
• Compression exercises to extend planning
• Retrieval grids to make words quick to grab

In 4–6 weeks of consistent work, you'll notice faster starts, fewer stalls, smoother rhythm, and more confidence.

Thanks for reading!

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References

Botes, E., Dewaele, J. M., & Greiff, S. (2020). The foreign language classroom anxiety scale and academic achievement: An overview of the prevailing literature and a meta‐analysis. The Modern Language Journal, 104(3), 731–754. https://doi.org/10.1111/modl.12607

DeKeyser, R. M. (2007). Skill acquisition theory. In B. VanPatten & J. Williams (Eds.), Theories in second language acquisition (pp. 97–113). Routledge.

Eysenck, M. W., Derakshan, N., Santos, R., & Calvo, M. G. (2007). Anxiety and cognitive performance: Attentional control theory. Emotion, 7(2), 336–353. https://doi.org/10.1037/1528-3542.7.2.336

Horwitz, E. K., & Young, D. J. (1991). Language anxiety: From theory and research to classroom implications. Prentice Hall.

Horwitz, E. K., Horwitz, M. B., & Cope, J. (1986). Foreign language classroom anxiety. The Modern Language Journal, 70(2), 125–132. https://doi.org/10.2307/327317

Indefrey, P. (2011). The spatial and temporal signatures of word production components: A critical update. Frontiers in Psychology, 2, 255. https://doi.org/10.3389/fpsyg.2011.00255

Indefrey, P., & Levelt, W. J. M. (2004). The spatial and temporal signatures of word production components. Cognition, 92(1–2), 101–144. https://doi.org/10.1016/j.cognition.2002.06.001

Levelt, W. J. M. (1989). Speaking: From intention to articulation. MIT Press.

Nation, I. S. P. (2013). Learning vocabulary in another language (2nd ed.). Cambridge University Press.

Skehan, P. (2021). Second language task-based performance: Theory, research, assessment. Cambridge University Press.

Swain, M. (2005). The output hypothesis: Theory and research. In E. Hinkel (Ed.), Handbook of research in second language teaching and learning (pp. 471–483). Routledge.

Tavakoli, P., & Wright, C. (2020). Second language task repetition: Task‐specific versus general effects. Studies in Second Language Acquisition, 42(1), 115–145. https://doi.org/10.1017/S0272263119000294