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How languages interact

Article explaining why mistakes bilinguals might make in sentence construction in one language often reflect their knowledge of additional languages.
Children sitting on the floor in a classroom setting raising their hands
© University of Reading

Do you recall an instance when a multilingual child said something to you using a slightly odd turn of phrase or strange arrangement of words?

Languages package semantics (meaning) into linguistic structure (grammar) in different ways. Bilingual children are learning two languages – two ways of communicating, each with their own set of rules. Both languages are always active to some extent, and they can overlap and influence each other. This is called cross-linguistic influence.

When the languages overlap and their respective structures are different, it can lead to unusual turns of phrase, or strange word orders in the child’s speech and writing. These can sound like errors to monolinguals, or to individuals who don’t share the same languages. However, if you look closely at the child’s languages, these ‘errors’ turn out to be a predictable aspect of bilingual language development.

Languages crossing over: cross-linguistic influence

Languages like English or Spanish use articles.

The pen is on the table. El bolígrafo está en la mesa.

But other languages, such as Ukrainian, don’t have articles at all. The sentence ‘кіт ганяється за мишею’ literally translates into ‘cat chasing mouse’. For a child who has Ukranian as one of their languages, dropping articles when speaking English would be a predictable example of cross-linguistic influence. It may sound odd initially, but if you know a little about the Ukrainian language, it makes sense. For a child who has been communicating effectively without articles their whole life, using them may not seem obvious when they start speaking English.

In addition to making a distinction between definite (‘the’ in English) and indefinite articles (‘a/an’ in English), many languages, such as Spanish, French and German, also mark gender (feminine, masculine, or neuter) and number (singular and plural) on articles. Speakers of these languages are used to having gendered language, even for objects. So the sentence ‘Lavons la table, elle est sale’ translates literally to ‘Let’s wash the table, she is dirty.’ This sounds odd to the monolingual English ear but is common in speakers of languages with gendered articles.

Being mindful of cross-linguistic differences can go a long way towards understanding what may, at first, appear to be errors but are in fact the predictable result of the interaction of a child’s two languages.

In addition to grammar, knowledge of vocabulary can be shared between languages. Some words in different languages share common roots and have similar meanings and pronunciation. These are called cognates (as you’ll remember from Step 2.11). Cognates can be helpful for children learning a new language.

English ‘banana’
French ‘banane’

But they can lead to mistakes in the case of ‘false cognates’, which are also known as ‘false friends’. This is when two words from different languages sound similar but do not have similar meanings. An example of this is the Spanish word ‘embarazada’. As an English speaker, can you guess what it means?

‘Embarazada’ translates to ‘pregnant’. It has nothing to do with being embarrassed! False cognates can be misleading for a bilingual child. Imagine a Spanish child’s confusion when they think their teacher is telling them not to be pregnant!

These examples show why errors that may look random superficially, are actually the predictable outcome of applying the structure and meaning of one language to another.

letter cards which can be matched with pictures. For example m matched to a picture of a moustache

Languages mixing: code-switching

Another result of having two active languages is code-switching. We want to debunk the myth that when children are mixing languages, they are doing so because they are lazy or incompetent. In fact, code-switching requires excellent knowledge of, and the ability to use, the grammatical rules of two languages. It is also dependent on the socio-linguistic environment. Children, just like adults, will code-switch in circumstances where it’s appropriate to do so and where they will be understood. For example, a child whose family speaks their heritage language as well as the societal language, will code-switch at home more than at school. At school, they know they won’t be understood because most people there don’t speak their heritage language. Knowing two languages can be an advantage because, where knowledge of a particular word or concept fails, the other language can fill the gap. Code-switching can be a resourceful solution to a knowledge gap rather than a sign of linguistic confusion. Many young people also code-switch just for fun, even if they know what they want to say in both languages!

Languages building on each other

Studies show that single language vocabulary (the number of words a child knows in each language separately) in bilingual children tends to be smaller than that of their monolingual peers1. This is unsurprising as the time and experience of bilingual children is shared across two languages and across different contexts. However, bilingual children’s bilingual vocabulary (all words in both languages) is often larger than the vocabulary of monolingual peers. The size of a child’s vocabulary is very important for general language skills, for learning to read and write, and for listening and reading comprehension. So focusing on both the number of words a child knows, and on how well they know them, is important for bilingual children across their two languages, just as it is for monolingual children in their single language.

It’s important to understand that a bilingual child’s general knowledge is not weaker simply because they do not have a word for each concept in both of their languages. It is to be expected that, for some concepts, they may know the word in just one of their languages. For example, for school-related concepts, they will have words mostly in the language of their schooling. For words to do with family life and culture, they may have words mostly in their heritage language. As children’s exposure to each language increases, they will accumulate words in both languages for the same concept.

It’s also important to remember that a child learning a second language is not starting from scratch; they have a wealth of conceptual knowledge that has already been packaged into one language which they can rely on when learning a second. For example, when learning the word ‘hat’ in a new language, they may well already know what a hat is and what it’s used for; all they need to learn is how it sounds (and possibly its spelling).

In summary, multilingual children are likely to make some errors in their spoken and written language that are not typical of monolingual language development, but these are a predictable outcome of bilingual language development. It’s useful to consider which languages they have and how they may interact to affect their speech and writing. Next time a multilingual child says something in English that sounds unusual, ask yourself what that reveals about their other languages.

Share your experience

In the comments below, can you give us an example of a sentence or turn of phrase you’ve heard or used, which is borrowed from or affected by another language? Are there any phrases that would make sense to you but not to someone unfamiliar with your language?


  1. Hoff, E., Core, C., Place, S., Rumiche, R., Señor, M., & Parra, M. (2012). Dual language exposure and early bilingual development. Journal of Child Language
© University of Reading
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Understanding Multilingual Children's Language Development

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