Speaking two languages literally changes the way we see the world, and bilingual speakers think differently to those who only use their native tongue.

The new research by Panos Athanasopoulos, Professor of Linguistics and English language at Lancaster University, has found that bilinguals think and behave like two different people, depending on the language context they are operating in.

Bilingual speakers can also switch flexibly between the two different mental states, and this gives them an advantage over people who only speak one language, the research has shown.

Professor Athanasopoulos said: “Our research looked at people who can speak both English and German, and showed that bilinguals think and behave like two different people, depending on the language they are using.

“We found that speaking different languages affected people’s memory of events, and impacted on the way they would carry out simple tasks.

“Our findings show that if you asked someone a question in English, and then repeated the same question in German, it’s very likely they would give completely different answers.

“Fluent German-English bilinguals categorise events according to the vocabulary constraints of the language in which they are speaking. In German, speakers tend to focus on the beginnings, middles, and ends of events. In English, speakers often leave out the endpoints and focus in on the action.

The research involved showing bilinguals video-clips of people completing everyday tasks, like walking from a supermarket and getting into a car, and asking them to describe what they saw.

When speaking English the participants zoomed in and focused on specific actions, describing the clip as a ‘woman is walking’. Whereas when speaking German, the participants tended to zoom out and describe the complete action – they would recall the woman leaving the supermarket and getting into her car.

Professor Athanasopoulos explained: “The results show that language clearly has a big effect on what we notice and how we see the world around us, and there is no doubt that language shapes our thinking.”

The research has also shown that bilinguals’ second language is always active in the background, and it gives them a “brain boost”, as they become trained to think more effectively and switch between the two languages.

Professor Athanasopoulos’ research, which has just been published in the journal Psychological Science, was undertaken in England and Germany, and compared groups of German and English undergraduate students. Some students only spoke their native tongue, while others spoke both German and English. Comparing groups of students ruled out the possibility that culture, rather than language, affected the way the participants saw the world.