A nudge in the right part of the brain could see foreign language basics come flooding back, researchers have said after a study suggested people who sat their French exam decades earlier had the same proficiency as recent school leavers.

Linguistics experts said their survey of almost 500 people appeared to show no change in ability to use language over time, contradicting the common “use it or lose it” adage.

The University of York study saw participants who took French GCSE or A-levels between the 1970s and 2020 completing a French vocabulary and grammar test.

Participants were asked whether they had used their French knowledge in the years since their exams, and anyone who had studied a language later on in life was excluded.

Researchers said while grammar is learned in a similar way to riding a bike, using a kind of muscle memory, vocabulary knowledge is often part of a densely connected network, meaning that a slight nudge in the right part of the brain can see words come flooding back.

The research findings, published in the journal Language Teaching, suggested the participants who had taken their exam 50 years ago and not used French since then, performed at the same level as recent school leavers, and even as well as those who occasionally used the language.

In times of necessity, such as at an airport or in a health emergency abroad, the study also showed that people were generally able to recall the correct foreign language words at short notice, researchers said.

They said this suggests people’s brains only needs a small amount of motivation to recall the learning they have had.

Professor Monika Schmid, head of the university’s department of language and linguistics, said: “We often say if you don’t use a language, you will lose it, but this doesn’t seem to be the case.

“The knowledge of language is astonishingly stable over long periods of time, compared to other subjects such as maths, history or sciences.

“This is likely because of the way language is stored in memory.

“Vocabulary is memorised in the same way that facts, dates and names are, for example, and whilst this memory is vulnerable to erosion, grammar is learned in a similar way to riding a bike, a kind of muscle memory, which is much more stable.

“Vocabulary knowledge, on the other hand, exists in a densely connected network, which means that we need only be reminded of a word that sounds similar to a foreign language word for our brain to recall it, a slight nudge in the right part of the brain and it comes flooding back.”

The professor said that because there are not distinct areas of the brain for different languages, parts of the English language “will overlay” with parts of the brain where other language learning has been stored.

She said: “If you hear the word ‘apple’ in English, mental representation of the word ‘pomme’ for apple in French will get a small amount of stimulus each time you say it in English.

“This stimulation is even higher if the two words sound similar in both languages.”

While people are unlikely to become suddenly fluent after years of not using a language, researchers said their work suggested that the basics for a language stay in the memory and so should not take too much learning to pick up again.

Prof Schmid said she hoped people might be encouraged by the research to look at refresher language lessons, rather than staying away due to concerns around “the more ‘boring’ elements of the courses, such as grammar”.

She said: “We hope that it might encourage more people to pick foreign languages back up if they knew it would only take a short amount of time in refresher lessons to bounce back to the original level.”