How do people agree on when to switch between languages?

Research Digest by Michela Bonfieni

A recent study reveals how bilinguals who speak the same two languages implicitly agree with each other on when to switch between their languages. The study also shows that switching between languages in the middle of a conversation is as natural and systematic as any other aspect of language.

Bilingual speakers often use bits of their two languages in their sentences. For example, speaking about taxes and savings, two Spanish-English speakers may go about like this:

Speaker 1: “qué dinero?” (‘what money?’)

Speaker 2: “el dinero ese que nos van a dar with the taxes.” (‘the money that they’re going to give us with the taxes.’)

This behaviour is very frequent among bilinguals who live in contexts where both their languages are used. Researchers on bilingualism refer to this as ‘code-switching’, and have dedicated a lot of attention to understand the way it works. Some of the questions they are more interested in are: how people agree on when it is OK to go from one language to the other; and how people avoid getting confused when switching between their languages.

Two researchers at the Pennsylvania State University (USA) decided to look at a big data-set of Spanish-English bilinguals to answer these questions. They selected a huge collection of transcribed conversations between Spanish-English bilinguals and analysed what happened in each conversation when the two speakers inserted one or more words from Spanish in an English sentence, or the other way around.

Specifically, they wanted to see if people were more likely to switch between languages if the person who they were talking to had switched between languages in the same conversation. In other words, they wanted to see if bilingual speakers somehow imitate each other when switching between languages. We all imitate each other to some extent when conversing: we choose the same words, or the same type of sentence, sometimes we adopt a similar accent or even intonation. Researchers call this type of linguistic imitation ‘priming’, and suggest that it is a fundamental mechanism to adapt to the environment and understand each other.

In this study, the two researchers showed that bilinguals were indeed more likely to switch between languages not only if it had happened in the previous sentence, but even if words from the other language had been used as far as ten sentences before. This suggests that they did imitate each other in the long run. Interestingly, though, the researchers also found that people would also ‘imitate themselves’, that is to say, that speakers were consistent in their combined used of the two languages, even when speaking to a different person. This first result suggests that choosing to switch between languages is a consistent behaviour. It also shows that people adapt their choices to the context and to the person they are talking to.

Moreover, the researchers were interested in understanding how the speakers in their study were able to keep one of the two languages as a reference point. What they call the “language of reference” is the language in which the majority of grammatical bits are expressed when switching – bits of the language that keep sentences together, such as the words ‘that’ and ‘the’, as well as verbs expressing actions but also time (for example, ‘ran’ as opposed to ‘run’ conveys information about the past). In other words, they wanted to understand whether switching between languages has some consistency grammatically, or whether ultimately speakers get confused as to what language they are using exactly. Their analysis showed that speakers were choosing the reference language consistently not only with respect to the previous sentence, but to up to the last ten sentences, and consistently within and between sentences.

Switching between languages is a frequent and visible phenomenon in bilinguals, and shows that the two languages of bilingual speakers are always active. But this study shows that this behaviour is not different to the way language works in general, and that it is not random but consistent, and probably useful to the mechanism of adaptation both to the environment and other speakers, so as to ultimately achieve successful communication.

This study was published in the Journal of Memory and Language by Melinda Fricke and Gerrit Jan Kootstra. You can read it at:

Research participants wanted – bilingual adults

We are looking for bilingual participants. If you live in Edinburgh or the Central Belt of Scotland, and you and your partner or housemate are both bilingual and switch languages in everyday conversation, you could help us!

Please contact Dr Mariana Vega-Mendoza at, who will be happy to send you more information. Your help is greatly appreciated! Each couple who participate will receive a £25 Amazon voucher at the end of the study.

Languages: English, Spanish, Polish, French, Portuguese, Arabic, Croatian, Czech, German, Mandarin, Russian, Swedish

Closing date to sign up: 20 June 2017

Healthy Linguistic Diet


Post by Dr Thomas H Bak

One of the things that I miss most in the current debates on bilingualism is the lack of interaction between cognitive and social scientists. Both disciplines do important work in this field, but it is very rare that they meet, exchange ideas and discuss their respective findings, let alone develop joint concepts and theories. This is one of the reasons why I was so delighted to be invited by the European Commission, Directorate General Education and Culture to join the meeting of the 4th Thematic Panel on Languages and Literacy in September 2016 in Brussels. This meeting as well as the subsequent one in January 2017, at which I was invited to give a keynote lecture, gave me a chance to interact directly with people coming from very different professional background, working with different populations and using different methodologies.

A particularly important encounter for me was that with Dina Mehmedbegovic, who gave a keynote lecture at the September 2016 meeting. Dina’s background is in school education and she has studied in detail the attitudes to minority languages in England and Wales, which she documented in her book published in 2011. One of the concepts she developed was that of a “healthy linguistic diet[Read more…]

Bilingualism Matters at Edinburgh Fringe 2017

We are delighted that our Director, Professor Antonella Sorace, and our Deputy Director, Dr Thomas Bak, are both challenging Edinburgh Fringe audiences this August with surprising findings from research, as part of the 2017 Cabaret of Dangerous Ideas, organised by Beltane Public Engagement Network. [Read more…]

Our Annual Event 2017

By: Mariana Vega-Mendoza & Madeleine Long

On Friday 12 May 2017, Bilingualism Matters hosted its Annual Event at the University of Edinburgh’s Informatics Forum. The event brought together professionals and researchers from areas such as education, neuroscience, and policy as well as members of the public.

The programme kicked off with registration and networking followed by a wonderful schedule of short talks hosted by Àdhamh Ó Broin. The first talk was by the Centre Director, Prof Antonella Sorace, [Read more…]

Survey on bilingualism and autism – May 2017

Online survey, the ABC – Autism and Bilingualism Census, designed for any adults (over 16 years-old) on the autism spectrum, monolinguals and multilinguals alike:

Bérengère Digard, a PhD student from the University of Edinburgh has reached out to us to help her with her research project. She is interested in the relationship between bilingualism and the autism spectrum; you can read more about her research on her webpage:

Bilingualism, Autism and the Brain

She just released an online survey, the ABC – Autism and Bilingualism Census, designed for any adults (over 16 years-old) on the autism spectrum, monolinguals and multilinguals alike. If you wish to help her by taking part in her project, you simply have to follow the link below. Completing the survey should take you between 10 and 15 minutes, maybe a bit more if you speak more than 2 languages.

Bilingualism Matters with ‘Little Linguists’ at Heathrow Airport

This Easter, we worked with Heathrow Airport to promote language learning for children, as part of their ‘Little Linguists’ scheme. Our Director, Professor Antonella Sorace, advised in the development of packs of fun flashcards in different languages, designed to spark an interest in language learning for the thousand of families passing through the airport over the Easter 2017 weekend. [Read more…]

Irish Gaelic: political football or treasure?

Post by Dr. Mimo Caenepeel

A few weeks ago, a sideways reference in a larger news item about the current crisis in Northern Ireland caught my attention: the newsreader reported that  ‘support for the Irish language’ was one factor in the complex breakdown of relations between Sinn Féin and the DUP. A quick online check gave me a bit more information. Just before Christmas, the DUP’s community minister Paul Givan decided to withdraw £ 50,000 in funding for an Irish Language (or ‘Irish Gaelic’) bursary scheme. Although that decision has since been reversed, Sinn Féin at the time called it ‘the straw that broke the camel’s back’.

While arguably small fish in an ocean of news, this struck me as an interesting example of the impact of community language issues, not just on daily life but also on political processes. A ‘community language’ is a language used as their primary language by a community of people on a daily basis. While the number of people in the Republic of Ireland and Northern Ireland who claim to have some knowledge of Irish is increasing (especially in urban areas like Dublin), the use of Irish as a community language is contracting; in fact, Irish is expected to disappear as a primary language by 2025. That puts Irish Gaelic (together with Scottish Gaelic) on the list of UK languages that are ‘definitely endangered’. [Read more…]

Not only the quantity matters: the importance of quality of input in language development

Sharon Unsworth talks about linguistic input in bilingual development

Post by Michela Bonfieni

Last week, the Linguistic Circle at the School of Philosophy, Psychology and Language Sciences (PPLS) at the University of Edinburgh hosted a talk by Sharon Unsworth, Associate Professor of Second Language Acquisition at the Radboud University, the Netherlands. Born in Lancashire, Unsworth completed her PhD in Utrecht with a dissertation on the differences between adults and children in language acquisition. Aside from teaching, she is now the head of a research project exploring the cognitive and developmental aspects of multilingualism.

Sharon Unsworth’s research is aimed investigating which factors contribute to the successful acquisition of two or more languages in childhood. [Read more…]

Workshop: The selectivity of native language attrition

Venue: University of Edinburgh
Date: 13-14 October 2017

Bilingualism Matters at the University of Edinburgh is pleased to host this two-day workshop “The selectivity of native language attrition” as part of the ESRC-funded First Language Attrition Seminar Series (ES/M001776/1) led by Monika Schmid (University of Essex).

Meeting Description

Very broadly, language attrition can be defined as changes in a speaker’s native  language (L1) as a result of increased use of another language (L2). Among the most intriguing questions in research on bilingualism is the selectivity of L1 attrition in first-generation speakers. What exactly changes in the L1?  Why are some linguistic properties more vulnerable than others to change under conditions of diminished exposure and use? Are these the same properties that are variable in heritage speakers, who may have experienced language attrition at an earlier age? An understanding of the relationship between L1 attrition and L2 acquisition in late bilinguals can advance our understanding of language and cognition in multilingualism.

We invite submissions on a large range of topics related to the relationship between L1 attrition, heritage languages, and generational/diachronic change. Submissions from a variety of backgrounds are welcome, such as linguistics, psycholinguistics, sociolinguistics, and cognitive neuroscience.

Confirmed Invited Speakers

Kinsey Bice (Penn State University)
Laura Dominguez (University of Southampton)
Janet Grijzenhout (Universität Konstanz)

Important Dates

Abstract submission:               1 March – 2 May 2017 (extended)
Notification of acceptance:    15 May 2017
Early bird registration:            1 September – 10 October 2017
Seminar:                                    13–14 October 2017

Organizing committee

Antonella Sorace (University of Edinburgh, Bilingualism Matters)
Roumyana Slabakova (University of Southampton)

Call for Papers

A panel of expert reviewers will choose abstracts for talks (30-minute talks, 20 minutes presentation plus 10 minutes discussion) and posters. Abstracts should be 500 words in Times New Roman (12 point), excluding tables and references, on one A4 page. Figures, tables, examples and references can be on a second page. Please submit anonymous abstracts to EasyChair at the following link:
Indicate a preference for oral or poster presentation. The application will ask for the title, the name(s) of author(s) and their affiliation(s) separately.