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Why can I understand a language but not speak it?

Benedict Grima · Last updated 8 October 2026

You find yourself asking: “Why can I understand a language but not speak it?” This question plagues a lot of passive bilinguals (for example, children or grandchildren of Polish immigrants to the US), and the reason is that understanding and speaking are two different skills.

In my experience, most of the ways people study a foreign language train only the understanding, not the speaking skill. When you listen, the word lands and the surrounding context helps you work out what it means. When you speak, you have to find every word yourself, fit it into a sentence and say it while someone waits. That’s a lot harder.

You start to close the gap between understanding and speaking when a) you practise pulling words out of your memory, not only recognising them, b) you learn whole phrases for the situations you actually find yourself in, and c) you say them out loud, often, before you feel ready.

If you understand Polish but can’t speak it, it doesn’t mean you are bad at languages. It is very common with a grandparents’ language, where you hear the language for years and answer in another one, like English.

My reason

I did not grow up with Polish. I am British, I grew up speaking English, and I am learning Polish to talk to my wife’s family, including her grandparents. Two words from my in-laws’ house are the clearest example I have of the gap between understanding and speaking.

The first is gołąbki (stuffed cabbage rolls, often served on festive occasions in Poland). It was shown to me at the Christmas dinner table, along with many other dishes. Since everything on the table was new and few items had any English equivalent, and I didn’t have to reproduce the word (just point at what I wanted to eat), I struggled to remember the name of the dish.

The second is zimno (cold). My mother-in-law taught it to me at Christmas while walking outside, with a brief self-hug and a shiver, and within a few hours I was using it to ask my wife’s youngest sister if she was cold in the fresh night air. Luckily, the time of year gave plenty of opportunities to reinforce this new word, so I remembered it easily, because it kept coming up.

In my opinion, the difference between gołąbki and zimno explains a lot of the gap between understanding and speaking. I had encountered gołąbki at the dinner table, along with many other new foods and traditions: minimal reinforcement, lots of competition, easy to passively understand, no need to reproduce the word to succeed. On the other hand, the whole family was experiencing zimno conditions day after day, given the season: plenty of context, reinforcement and necessity in reproducing the word myself.

Is it normal to understand more than you can say?

Yes. In 2008 the linguist Stuart Webb tested second-language learners in two directions. Could they translate a foreign word into their own language, and could they produce the foreign word when given its meaning? Overall, the learners understood more words than they could produce. When the marking asked for fuller knowledge of a word, the gap grew as the words got rarer. When a learner earned credit for partial knowledge, the gap was small.¹

A word of caution, though. This study tested single words, not conversations. It shows that the gap exists, but it can’t tell you how big it will feel when you open your mouth.

Why is speaking so much harder than understanding?

Because when you speak, it’s all on you to produce the language. Listening is passive: listening supplies the word, its sound and context to guess from. Speaking gives you a blank and a person waiting. I think three things make speaking the harder skill.

Finding the word

Recognising a word and recalling it are different skills, as I explain in Why do I keep forgetting new words in a language? When someone says herbata (tea), the sound does most of the work. When you want to ask for tea, you have to find herbata in your own head with nothing to prompt you, and a word you have only ever recognised is a hard one to produce yourself.

Building the sentence

Listening lets you ignore small decisions in favour of overall meaning. If you hear babcia or babciu, you know who is meant either way. When you speak, you have to choose. You learn you have to say Babciu! when you call your grandmother, and babcia when you talk about her, because Polish changes the ending of a word depending on its job in the sentence. Every sentence you speak is full of small choices like this one.

Saying it in time

A conversation moves faster than you can look things up. If you think of the sentence in English first and then translate it in your head, you are doing two jobs, which takes even longer. In my opinion, translating like that is the hallmark of a beginner, and the ultimate aim is to build the sentence in the foreign language itself.

Why do so many people understand a grandparents’ language but not speak it?

Usually because they hear the foreign language for years (in context) and answer in another language, such as English. Researchers call people who were raised in a home where one language is spoken, and who later switched to another dominant language, “heritage speakers”.² Many heritage speakers understand the family language but speak little of it, which is known as receptive (or passive) bilingualism. The researchers who study receptive bilingualism describe it as highly common but little studied.³

However, in 2022 Tanja Anstatt and Ursula Mikić did study 10 receptive bilinguals whose family language was Polish and who lived in Germany. All 10 followed spoken Polish well up to an intermediate level, and some did very well with much harder speech. The task that asked them to produce single words gave the lowest results of all the tests, which shows a wide gap between what they understood and what they could produce. Those who followed the hardest speech best also tended to be the ones whose parents had spoken to them directly in Polish more often in childhood. The authors add that how much a person can say is not a reliable measure of how much they understand.³

A word of caution, though: 10 people is a small group, so the study shows what the gap looks like, not how big it might be for you, and it can’t prove why it happens. In my opinion, the explanation is simple and circumstantial. Understanding needs only listening, and a grandparent who understands your English rarely needs you to answer in their language, so speaking can stay behind for years.

How do I go from understanding to speaking?

By practising in the direction you are missing: from meaning to word, out loud, and in whole sentences. The direction matters. In 2009 Webb had students of English in Japan learn word pairs in two ways: receptively, from the word to its meaning, or productively, from the meaning to the word. Practising from meaning to word gave larger gains in what the students could produce, and practising from word to meaning gave larger gains in recognising what a word means. Webb concluded that if you can only use one method, meaning to word might be the more effective one.⁴ I note that the study measured single words, so it can’t tell us how well the students spoke.

These are the 5 things I would do this week:

• Practise from meaning to word, not word to meaning. Cover the foreign word, look at the English and recall the foreign word out loud before you confirm what it is. The “Review” feature in the Lumessa app does this in some of its questions. It shows you the English and asks you to type the word in the target language, because pulling a word out of memory is what makes it stick. Typing is not speaking, so the saying out loud is still up to you.
• Learn the words for the people you want to talk to. For a grandparent, that means the kitchen and the family: babcia (grandmother), dziadek (grandfather), kuchnia (kitchen). Words tied to a real moment stay with you. I remember grzyb (mushroom) because I learnt it mushroom-picking in the forest with my wife’s grandparents. I wrote more about choosing words this way in How to learn Polish to talk to your partner’s family.
• Rehearse whole phrases for the conversations you know are coming. Before a visit, choose the handful of sentences you will need and practise them until they come without thinking. Dziękuję, babciu, było pyszne (Thank you, Grandma, it was delicious) was a good one to have ready after eating the gołąbki.
• Say your day out loud. Describe what you are doing, in the language, to nobody in particular: Robię herbatę (I’m making tea). Each sentence is speaking practice that needs nobody else.
• Speak to a real person early, accept that you will get things wrong, and don’t feel embarrassed. My wife’s English came from school lessons, reading novels and speaking practice with online tutors. The speaking practice is the part a novel cannot give you. And, in my experience, people generally respect anyone learning their language.

Start from what you already understand

If you can already understand a foreign language, you have a foundation. You know its sound, many of its words and roughly how its sentences are pieced together. What is missing is practice in the other direction, and you can add that on purpose. Say phrases out loud, starting with the meaning and finding the word/phrase in the target language. Repeat again and again, until the words you can recognise become words you can actually use when the context requires.

The words you need depend on who you want to talk to, which is why the Lumessa app asks why you are learning: family and heritage, someone you love, travel, work or study, or simple curiosity. Your most useful vocabulary is taught first.

See how Lumessa works