Following on from our previous post on Bimodal Bilingualism and publication success of a related case report, our Lab members have been involved in supporting a further intra-operative language assessment of a bilingual patient, which required the design of a bespoke set of tasks (take a peek at the paper here, if it’s sparked your interest).
You may be wondering why bilingual language assessments require a bespoke task design, and so this blog post is going to address this question by debunking a few myths and letting you in on bilingualism’s best kept secret(s).
What is bilingualism and who counts as bilingual?
Bilingualism, broadly defined, involves the acquisition and use of two or more languages in daily life. There is no single definition of bilingualism since it can be seen as an evolving experience throughout one’s life. Yet, a common misconception persists that categorises bilinguals as having equal proficiency in both languages. This popular belief cannot be further from the truth. In reality, bilinguals know their languages to the extent they need them and often have one language that is more dominant than the other one.
Given such a broad (or vague) definition of the term, it may be no surprise that measuring bilingualism – that is, who counts or doesn’t count as a bilingual – is quite complex.
On the one hand, there are various skills involved in language that may need to be taken into account in such an assessment, such as reading, writing, speaking, and listening, as well as knowledge areas like vocabulary and grammar (see here for a discussion on the difficulty of counting bilinguals). Individuals often excel in some areas more than others, for instance, being able to hold a conversation in two languages equally easily but struggling, or even not being able, to write or read in one of their languages, especially if they were never formally taught to do that. Instances like this make it difficult to classify people strictly as monolingual or bilingual. Even lifelong bilinguals show variability in their language proficiency across the different skills and knowledge areas.
On the other hand, estimates of bilingualism are often influenced by attitudes towards it – and these attitudes vary by region. In Europe, for instance, high standards are set for who is considered bilingual, often expecting perfect knowledge and no accent across a bilingual’s two languages. In contrast, the United States have a more inclusive view of bilingualism, recognising the diverse language pairings and the fact that about 1 in 5 people across the country use two or more languages in their daily lives.
How many people then count as bilingual?
Now, here is the best bit: speaking more than one language is the norm rather than the exception and it is estimated that more than half the world’s population is bilingual (Grosjean, 2010). How can one explain such large numbers of bilinguals? One reason is simply that many countries house numerous languages: 722 in Indonesia, 445 in India, 207 in Australia and so on. Contact between communities means learning other languages or, at the very least, acquiring a common language of communication and hence being bilingual. Educational policies, political fluctuations, religious, social, and work-related choices of individuals and their families all contribute to the ongoing growth of bilingualism across the world.
Bilingualism is present on all continents, in all classes of society, in all age groups, so let’s put some more precise figures to this. Looking at Asia and Africa, to start with, we know that many people are bi- or multilingual although a definite estimate is still lacking. In North America, some 35% of the population in Canada is bilingual and although the percentage is smaller in the United States – close to 23% in 2018 – this still corresponds to an estimated 70 million inhabitants. Bilingualism in the US is very diverse, pairing English with Native American languages, older colonial languages, recent immigration languages, and so on (see here). This diversity is often characterised through the term ‘societal bilingualism’ and is also strongly manifested in Europe.
In Europe then, a bit more than half of the population is at least bilingual. As such, smaller countries such as Luxembourg, Switzerland, and The Netherlands house many bilinguals whereas larger countries such as France and the United Kingdom have fewer of them. In the UK, almost 40% of the adult population is reportedly able to hold a conversation in a second language (Languages for the Future Report, British Council, 2017), some of which are reflected in an ever-evolving landscape of the languages spoken in England and Wales (see Figure 1).

Moving closer to our city, Bristol, at least 91 different languages were spoken by its residents in 2022 (Insight, Performance and Intelligence Service), so you do the maths! It is no surprise then that the clinical teams we work with report having cared for patients with a range of different languages, as displayed in Figure 2, necessitating a very careful and bespoke task design for assessment of their language skills.

What makes bilinguals different from the rest/so special?
There are many myths surrounding bilingualism. Apart from the ones already mentioned, we bring up a further three, but you can read more on this topic via the links we provide at the end of this blog.
- Many people mistakenly believe that true bilinguals do not have accents in their languages and are excellent translators. This is far from being true. Having an accent does not affect one’s bilingualism, however, translating specialised language can prove incredibly difficult for many bilingual speakers.
- Regarding children, there are several common misconceptions. One is that bilingualism delays language acquisition in young children. This was a popular myth in the first part of the last century, but there is no research evidence to that effect. On the contrary, research shows that bilingual children acquire language at the same rate as monolingual children. We also now know that early exposure to multiple languages brings about multiple advantages ranging from effective communication skills, enhanced development of working memory, and a delayed onset of cognitive decline typically observed in dementia.
- Another misconception is that bilinguals always mix their languages. In reality, both bilingual children and adults adapt to their environment and the situation they’re in. When they interact in monolingual situations, e.g. with Grandma who doesn’t speak their other language, they will respond monolingually; if they are with other bilinguals, then they may well code-switch.
The bilingual paediatric patient that our team followed, fell into this latter category. He learned both English and Polish simultaneously during early childhood and grew up speaking both fluently. For him, as for many other bilinguals, the ability to alternate between these two languages is key for everyday life.
What is language switching and how does it work?
Bilinguals’ ability to change between languages, voluntarily or not, and depending on the context they find themselves in, is called language switching. Bilingual people manage two or more active languages in their brain (or ‘mental lexicon’), choosing to speak the appropriate one based on any given situation. For example, they might use English at work or school and their native language at home. Language switching also occurs within a conversation, when bilingual people are speaking with each other. They might use words or expressions in a different language that better convey the meaning of what they wish to say (see here for more content on language switching).
Language switching is not only key for effective communication but also has beneficial effects for bilingual people’s brain health, as their brain is constantly engaged in a process of suppressing an irrelevant language, while facilitating the relevant one. This recurrent process of managing multiple languages has been shown to enhance people’s cognition and executive skills, such as multitasking, focusing attention and problem-solving. Additionally, switching languages throughout a bilingual’s lifetime has been evidenced to boost their brain flexibility (neuroplasticity, in scientific terms), helping to protect against cognitive decline and dementia onset in older age.
Given the importance of language switching for so many facets of a bilingual’s life, it is imperative to protect such a skill, especially within a clinical setting. And that’s what our team’s ongoing work is trying to do.
Stay tuned for more updates on this and other aspects of our work!
Further reading on the topic
- François Grosjean’s website and resources: https://www.francoisgrosjean.ch/blog_en.html
- Myths about Bilingualism
- Raising Bilingual Children
- Amazing map reveals the 60-plus languages spoken throughout Bristol
- Benefits of being bilingual
- Executive Functions
- Bilingualism Is Associated with a Delayed Onset of Dementia but Not with a Lower Risk of Developing it: a Systematic Review with Meta-Analyses
- A Systematic Review on the Possible Relationship Between Bilingualism, Cognitive Decline, and the Onset of Dementia
