For years people around the world have learned English by watching Hollywood movies and costume dramas on the BBC. Now British monoglots have one less excuse for not returning the favour: a new online tool that turns the streaming service Netflix into a sofa-based language lab.

Language Learning With Netflix (LLN), a tool that allows viewers to watch foreign language shows with subtitles both in the original language and English, and pauses automatically to allow the learner to absorb what they have just heard, has been downloaded by tens of thousands of people since its launch in December.

Amid growing concern over the falling number of pupils taking foreign languages in secondary schools, some linguists have hailed LLN as a dynamic way of harnessing the educational potential of Netflix, which has programmes in 26 languages in 190 countries, and aims to have 100 non-English language series in production by this year.

David Wilkinson and Ognjen Apic, the two independent developers behind the tool, began the project as a hobby a few years ago and launched their Chrome browser extension in December. A trickle of users has turned into a flood – in the last three weeks more than 30,000 people have downloaded the tool.

“We want to encourage people to use good habits,” Wilkinson said. “At an early stage, students should listen to the language as much as possible. Pump language into the ears and provide a translation that allows you to associate meaning with that.”

Wilkinson, who was born in Zimbabwe to English parents, began making his own materials seven years ago while learning Indonesian and Persian.

“There’s probably three languages I use quite often – I kind of enjoy them: Farsi, Russian and Spanish. The others I don’t really use very much,” he said, adding that he does speak English “most days”. “I spent a lot of the time studying languages on my own but I made mistakes and I wasted a lot of time with methods which weren’t effective.”

Wilkinson trained as a mechanical engineer before setting up a business selling bilingual books and started working on a precursor to LLN about three years ago. He discovered that Apic, a Serbian linguist, was doing the same thing, so they decided to team up. They picked Netflix because it offers such a wide range of shows in foreign languages, from the Italian crime drama Suburra: Blood on Rome to the Israeli political thriller Fauda via the Oscar-winning film Roma, set in Mexico City.

Roma film still. Photograph: Venice Film festival press

LLN helps users absorb the language they are trying to learn by allowing them to view two translations simultaneously – an automatic, machine translation which tends to be literal, and an official version made by a person who understands idiom.

But whether the tool can help reverse the longterm decline of foreign languages in British schools remains to be seen. Since 2004, foreign language GCSEs have been optional, and a BBC analysis published last week found that the numbers of children studying German and French had dropped by about two-thirds since then.

Katharina von Ruckteschell-Katte, director of the Goethe-Institut in London, said making language more fun by using “fantastic” tools like LLN would help.

“If I had had all these possibilities when I was young and learning French, Spanish and English I would have really loved it,” she said. “We at the Goethe-Institut, and all the institutions that teach foreign languages, do have this fear that in future all the robots will take over. I think it’s the other way around – we will still be teaching German, but we have to learn how to teach it together with these instruments.”

Apps such as Memrise, Babbel and Duolingo, which has 13 million users in the UK, are increasing in popularity. Duolingo said it had seen a 38% increase in UK users learning French and a 34% increase in users learning German since early 2017.

“We know people already watch foreign language Netflix shows with subtitles to improve their listening comprehension,” Sam Dalsimer, Duolingo’s head of PR, said.

“The LLN extension is a cool feature to enhance that experience. It seems primarily geared towards learners who have already acquired a decent baseline of vocabulary and grammar, and would be a great complement to learning with Duolingo.”

Not everyone is convinced, however. “You can’t learn a language like this,” said Mickael Pointecouteau, course manager at the Alliance Française in London. “You need a real teacher to speak to, and to practise listening. It’s a bit passive and focuses only on one skill.”

Wilkinson and Apic have ambitions to branch out to cover other platforms such as Amazon Video, but are currently fine-tuning the tool. They are adding an option to transliterate Japanese and Mandarin into Romanised subtitles and working on shows dubbed into different languages – the re-voiced scripts often do not directly match the subtitle translations of the original language.

Programmes to listen and learn

Benvinguts a la familia, Bankier van het Verzet, And Breathe Normally, Kita Kita.

Languages to learn with Netflix

Catalan

Benvinguts a la família (Welcome to the Family) – a dark comedy about a family being evicted from their home.

Dutch

Bankier van het Verzet (The Resistance Banker) – a second world war film about the Dutch resistance.

Filipino

Kita Kita – a romantic comedy about a tour guide who goes blind after her fiance cheats on her.

Icelandic

Andið eðlilega (And Breathe Normally) – a drama about the bond between a single mother and an asylum seeker.

Tamil

Radiopetti (Radio Set) – a drama about a partially deaf old man and the valve radio his father gave him.