Trilingual study shows how non-native languages interact with each other when multilinguals talk

People who speak more than two languages are more likely to mistakenly use words from the language they’re least proficient in, new research has shown.

The study, led by Dr. Angela de Bruin, from the Department of Psychology, looked at which of the other languages spoken by trilinguals “interfered” when they were speaking their second language.

Dr. de Bruin said, “Intuitively, you would expect these intrusions to mostly come from your most proficient language, for example the first language you grew up speaking from birth. However, our recent research shows that when having to use a less proficient second language, multilinguals actually experience more interference from another less proficient third language than from their native tongue.”

Interference

The study, conducted at the University of York and the Basque Center on Cognition, Brain and Language, looked at two groups of trilinguals: Spanish-Basque-English trilinguals in the Basque Country and English-French-Spanish trilinguals in the U.K.

Participants were asked to name pictures in their three languages in response to a cue. For example, when seeing the picture of an “apple” with the Spanish flag, they would have to say “manzana.” The participants were presented these pictures for a short period of time to make the task difficult.

The team then assessed which language interfered more when trilinguals had to use their second language. In both groups of trilinguals, participants more often accidentally used their third language than their first language, showing that this interference between non-native languages can be found across different trilingual groups.

Suppressed words

The research team also studied why this might be the case. In two other tasks, they tested how participants suppressed words in the other languages while using their second language. They found that the trilinguals suppressed words in their first language more than in their third.

Dr. de Bruin says, “This could explain why these trilinguals experienced more interference from their less proficient third language: they might have suppressed that language less, leading to them accidentally using that language instead.”

Many people are able to communicate in more than one language and approximately a quarter of the European population can even speak three or more languages.

Role and influence

The research conducted by Dr. de Bruin is based on personal experience. She says, “When I tried to speak German in Germany after moving to Spain I was trying to buy a bus ticket and I noticed I almost uncontrollably switched between German and Spanish and inserted Spanish words like ‘por favor’ without wanting to. Although my native language Dutch is very similar to German, this interference was not coming from Dutch but rather from Spanish, a language I was far less fluent in.”

She concludes, “This study shows that just knowing words in a language might not be enough to ensure fluent communication. It is also crucial to retrieve the words in the intended language at the appropriate moment and to avoid interference from the other language(s). Trilinguals might have less experience with, or might be worse at, suppressing a less proficient language and might therefore experience more interference from that language.

“Interestingly, whilst we often focus on the role and influence of a first language, our study highlights the importance of understanding how languages that are acquired later in childhood or adolescence can influence each other. Fluent communication in those languages might not just require a certain level of knowledge in that language but also efficient control over the other languages.”

The study is published in the Journal of Memory and Language.