Speaking two languages really could give you a split personality, researchers have found.
They say that many speakers have entirely different personalities in each of the languages they speak.
Previously research has even found those who are bilingual even see colours differently.
'Rather than ask whether speakers of different languages have different minds, he says, 'we ask, Can two different minds exist within one person?' said psycholinguist Panos Athanasopoulos of Lancaster University.
'The extent to which language affects this process has been the focus of a long-standing debate: Do different languages cause their speakers to behave differently?,' the team wrote.
'Here, we show that fluent German-English bilinguals categorize motion events according to the grammatical constraints of the language in which they operate.
Athanasopoulos and colleagues were interested in a particular difference in how English and German speakers treat events.
English has a grammatical toolkit for situating actions in time: 'I was sailing to Bermuda and I saw Elvis' is different from 'I sailed to Bermuda and I saw Elvis.' German doesn't have this feature.
As a result, German speakers tend to specify the beginnings, middles, and ends of events, but English speakers often leave out the endpoints and focus in on the action.
Looking at the same scene, for example, German speakers might say, 'A man leaves the house and walks to the store,' whereas an English speaker would just say, 'A man is walking.'
This linguistic difference seems to influence how speakers of the two languages view events, according to the research.
'First, as predicted from cross-linguistic differences in motion encoding, participants functioning in a German testing context prefer to match events on the basis of motion completion to a greater extent than participants in an English context.
'Second, when participants suffer verbal interference in English, their categorization behavior is congruent with that predicted for German and when we switch the language of interference to German, their categorization becomes congruent with that predicted for English.
'These findings show that language effects on cognition are context-bound and transient, revealing unprecedented levels of malleability in human cognition.'
Previous research found a similar result.
Between 2001 and 2003, linguists Jean-Marc Dewaele and Aneta Pavlenko asked over a thousand bilinguals whether they 'feel like a different person' when they speak different langauges.
Nearly two-thirds said they did.
Scientists have also found that regularly speaking in a second language makes you literally see the world in a different way.
Color perception is an ideal way of testing bilingual concepts because there is a huge variation between where different languages place boundaries on the color spectrum.