Language Delay, Learning Disorder, or Lack of Exposure?

Imagine a hypothetical situation: two children with identical cognitive abilities, physical characteristics and learning potential are learning to play musical instruments. One practises the guitar for two hours a day. The other also practises for two hours, but divides that time equally between the guitar and the drums.

After three months of consistent practice, would you expect both children to perform equally well on the guitar?

Probably not. Assuming all other relevant factors are equal, the child who spends twice as much time practising the guitar is likely to perform better on that instrument.

Now, let’s apply this comparison to language learning.

One brain, two languages, different experiences

Imagine two children with similar cognitive abilities and comparable overall exposure to language. One grows up speaking a single language, while the other grows up speaking two.

The monolingual child has more opportunities to practise their one language, while the bilingual child’s experience is distributed across two languages. This does not mean that bilingual children know less overall. It means that their knowledge and experience are distributed differently.

Research has shown that bilinguals can sometimes be slower than monolinguals when retrieving words in picture-naming tasks. Bilingual language processing involves particular demands, including the need to manage and select between languages that are simultaneously active. Bilingual speakers may also experience more tip-of-the-tongue moments (Albert Costa, The Bilingual Brain, 2017).

But what do these findings actually tell us? Does taking longer to recall a word mean that a child does not know it?

Not necessarily. The difference may be a matter of access and retrieval rather than a lack of underlying knowledge. These differences remind us that language performance is influenced by how the brain processes and retrieves linguistic information, not simply by how much a person knows.

There is another important factor to consider: the contexts in which children encounter and use their languages.

Does weaker performance in one language mean a language delay?

Not necessarily. A child can understand an idea fully and still lack the words for it in one of their languages.

Monolingual children may have more opportunities to develop vocabulary across a wider range of contexts in their dominant language. Bilingual children, meanwhile, may encounter particular topics more frequently in one language than in another.

Consider a bilingual child who takes music lessons in French. They learn the names of instruments, musical techniques and concepts through French. If they are later assessed on music-related vocabulary in English, they may struggle to name the same instruments or explain the same concepts in English.

Would this mean that the child lacks musical knowledge?

Of course not. The child may understand the concepts perfectly well but lack the corresponding English vocabulary, because they have had fewer opportunities to encounter and use these words in English. With appropriate exposure to music-related language in English, that vocabulary gap may narrow.

A gap in vocabulary in a particular language is not necessarily a gap in knowledge, understanding or learning ability.

The same principle applies to many other areas of children’s lives. A child who plays football and discusses sports mainly in their home language may perform poorly on an English-language assessment of sports vocabulary. A child who regularly cooks with their grandparents in another language may know the names of ingredients and cooking techniques in that language but struggle to retrieve their English equivalents.

Their performance reflects not only what they know, but also the language in which they learned it, the contexts in which they use it and the opportunities they have had to develop the vocabulary being assessed.

When does assessment mistake difference for difficulty?

Now imagine a bilingual child being assessed by a monolingual professional, such as a speech-language pathologist or a teacher, using an assessment tool designed for monolingual children. The assessment takes place in just one of the child’s languages.

The child performs well on familiar topics but struggles with vocabulary related to unfamiliar experiences. The professional observes a limited vocabulary, slow word retrieval or difficulty responding to particular questions.

How should these results be interpreted?

Without understanding the child’s language background, exposure and experiences, it can be difficult to distinguish between limited exposure to particular vocabulary, differences in language development and a genuine language difficulty.

A child who has never played a particular sport or discussed it in the language of assessment may not know the relevant words. Yet a standardised assessment may interpret this performance as evidence of a language delay.

When bilingual children are assessed against monolingual norms without appropriate consideration of their multilingual experiences, their abilities may be underestimated.

This is particularly concerning when assessment results inform decisions about additional support, specialist referrals or educational placement.

What does a fair assessment look like?

It looks at all of the child’s languages together, not their performance in just one.

To understand a bilingual child’s language development, we need to look beyond their performance in a single language. This means considering:

• All the child’s languages. What can the child understand, communicate and express in each language?
• Exposure and opportunities for use. How much experience has the child had with each language, and in which contexts?
• The distribution of knowledge. Which topics, concepts and vocabulary are more familiar in one language than another?
• Overall communication skills. How does the child communicate across languages and situations, not only in a structured testing environment?
• Development over time. How are the child’s skills progressing in relation to their language experience and developmental history?

Ideally, assessment should involve professionals who understand multilingual language development and can assess the child across all their languages. This may require collaboration with bilingual professionals, interpreters or other specialists who can help gather information about the child’s communication in their home languages.

Importantly, assessing all languages does not mean simply translating a monolingual test and administering it twice. Assessment tools, cultural expectations and language-specific norms all matter. A comprehensive evaluation should combine appropriate assessment methods with information from families, observations of the child’s communication and a detailed understanding of their linguistic environment.

A genuine language difficulty can affect a multilingual child, just as it can affect a monolingual child.

Multilingualism does not rule out a developmental language disorder or learning difficulty. But multilingualism itself should not be mistaken for evidence of one.