I understand English but can't speak it: what to do

You're watching a show and a character says We ended up staying until midnight. You get it instantly: they hadn't planned to, but they stayed until midnight. The next day, telling a coworker about your weekend, what comes out is In the end, we stayed until midnight. Correct and clear, but it's not the phrase you had just heard, and probably not the one a native speaker would use.

If this sounds like you, the most common diagnosis is "I need more conversation practice." Sometimes you do. But often the problem starts earlier: the expression is in your passive vocabulary and has never made it into your active vocabulary.

What's the difference between passive and active vocabulary?

Passive, or receptive, vocabulary is what you recognize when you hear or read it. Active, or productive, vocabulary is what you can pull out of your head and use when you speak or write.

It's not two separate boxes but a scale. Between "never seen it" and "use it without thinking," a word goes through several stages:

1. I've seen it, but I don't know what it means.
2. I understand it when it appears in context.
3. I understand it even out of context.
4. I can use it if I have time to think.
5. I use it naturally, at the pace of conversation.

Intermediate learners usually have lots of words in stages 2 and 3. That's why they understand almost everything in a show and freeze in a meeting.

Knowing a word also involves more than its meaning. In a 2005 study, researcher Stuart Webb measured five aspects of word knowledge: spelling, the grammatical patterns the word fits into, its associations with other words, its grammatical function, and the link between form and meaning. You can know what end up means and still not know that it takes an -ing form after it (ended up staying, not ended up to stay).

Why do you recognize the word but can't use it?

Because recognizing and producing are different tasks, and recognizing is easier. When you hear ended up, the context, the scene and the whole sentence help you. When you need to speak, you have none of that: it's just you, an idea in your own language and your memory.

Research confirms the gap between the two:

• In 1998, Batia Laufer compared two groups of students learning English as a foreign language, with six and seven years of school instruction, to see what changes in one year. Passive vocabulary grew considerably. Controlled active vocabulary, measured with a test in which students have to produce the word from clues, grew less. Free active vocabulary, measured by the words students used spontaneously when writing, showed no progress. And the gap between passive and active was larger in the more advanced group.
• In 2008, Stuart Webb tested Japanese university students with equivalent translation tests in both directions: from English into Japanese (receptive) and from Japanese into English (productive). Receptive vocabulary was larger than productive vocabulary. And, with strict scoring, the gap grew as the words became less frequent.

That last point explains a lot. You use basic words so much that they end up becoming active. Less frequent words you meet often enough to recognize, but not often enough for them to be available when you need to speak. It's reasonable to expect something similar with expressions like end up, come up with and run into: you hear them all the time, but almost never need to produce them. And they're what makes the difference between correct English and natural English. More about them in The words your English is missing.

A caveat: these studies were done with students in school or university settings, outside Brazil, and with specific tests. They don't directly measure an adult Brazilian learner in conversation. But the pattern (passive larger than active, and a bigger gap for less common words) shows up consistently.

If I understand it, don't I already know enough?

To understand, maybe. To speak, no. And understanding "well enough" often hides gaps.

In the 2008 study, the gap between receptive and productive vocabulary depended on how strictly answers were scored. When partially correct answers were accepted, it practically disappeared at each frequency level. When more complete knowledge was required, it showed up. The difference lies in the details: the exact form of the word and its precise meaning. To follow a scene, a rough idea is enough. To build a sentence, it isn't.

What should you practice to turn passive into active?

Production. If you only practice recognizing, you get better at recognizing. To be able to use a word, you need to practice the opposite path: start from the meaning and get to the English.

Research offers three clues, each with its own caveats:

• Production tasks pay off more, but take longer. In the 2005 study, Webb compared reading a word in sentences with a translation and writing sentences with it. With the same amount of time for both tasks, reading did better. When each person had all the time they needed, writing, which took longer, was more effective. Producing costs more, and pays off more if you give it the time it needs.
• Saying it out loud helps you remember. In 2010, Colin MacLeod and colleagues at the University of Waterloo, in Canada, demonstrated what's called the production effect: words read aloud during study were recognized more easily on a later test than words read silently. The caveat is that the effect appeared when people said some words aloud and read others silently; the authors' explanation is that the spoken words stand out more. It's not magic, but it's a concrete reason not to study with your eyes alone.
• Trying to remember sticks better than reviewing. Pulling the sentence from memory, instead of looking at it again, is one of the most solid findings about learning. It's explained in Why you forget the English you study.

What does this look like in practice?

Four steps, one sentence at a time. Here they are with three expressions many people recognize but don't use. The prompts are in Portuguese, the starting point for most of our readers; use your own language if it's different:

1. Start from the meaning. Look at the sentence in your own language, or picture the situation, and try to say it in English before checking.
2. Say the whole sentence, out loud. Not just come up with, but I need to come up with an excuse. The preposition, the verb tense and the rhythm come along with it.
3. Adapt it to your life. Change the subject, the place, the situation. A sentence about you is easier to remember and more likely to get used.
4. Use it for real the same week. In a conversation, a message, a meeting. The first time it will come out slowly. By the third, faster.

That's why dailyBe trains the sentences on your list in different modes: seeing, listening and speaking. Speaking mode is the closest to what this post argues for: producing the sentence out loud instead of just recognizing it. You say the sentence, the app uses speech recognition to show what it understood and, if something came out wrong, gives you a pronunciation tip spelled out the way a Brazilian would read it. And reviews follow the logic of spaced repetition: get it right and the sentence comes back later; get it wrong and it comes back sooner. Details in Features.

Where should you start?

Think of a conversation you had this week when the word just wouldn't come. What expression did you want to use? Pick five expressions like that, ones you understand but don't use, build a sentence of your own with each one, and say it out loud. Tomorrow, try to recall them starting from your own language. To fit this practice into a short, focused block of time, see How to study English vocabulary in 20 minutes a day.