Does bilingualism cause language delay?


What is bilingualism?

What are the benefits of being bilingual?

Do children exposed to two languages ​​from birth speak later?

How do I know if my child should have a language assessment?

In this post, we will try to find the answers to these three questions.


What is bilingualism?

Simply put, bilingualism is the ability to use two languages.

The degree of proficiency in the two languages ​​can vary from a minimal to a profound knowledge of both languages.

A person might be considered bilingual and only be able to speak, but not write, in the second language.

Some may have a profound knowledge of the native language and be able to read in another language.

Or someone might be bilingual and have perfect knowledge in all linguistic domains (writing – reading – listening – speaking) of two languages.

Here are some examples:

  • Laura’s first language is Italian, but she is able to ask for information in English when she travels around the world.

  • Hannah is able to communicate in both English and American Sign Language (ASL).

  • Steve can speak both English and Scots (language spoken in Scotland), perfectly.

Although all these cases are considered bilingual, when it comes to bilingualism there are distinctions regarding the order of acquisition of the two languages.

Simultaneous bilingualism is spoken of when a child is exposed to two languages ​​at the same time, usually from birth. This is the case when a child’s parents speak two different languages.

On the other hand, there is consecutive bilingualism when the child is first exposed to one language at home, and subsequently exposed to a second language when he/she starts school. For example, children from a Romanian family living in London.

In this case, it is possible to speak of Language 1 (L1) which is the native – best known – language and Language 2 (L2) which is the later introduced language.

Consecutive bilingualism may also occur when a person lives in one country up to a certain age and then moves to another country to study or work (like I – and other thousands of other people – did).

Today, around 70% of the world’s population is considered to be bilingual. Contrary to what was thought in the early 1900s, being bilingual does not cause cognitive or language problems. Nowadays, numerous studies speculate that being bilingual can have advantages.

What are the benefits of being bilingual?

First of all, being able to speak two languages and understand two cultures has the advantage of increasing job opportunities.

For example, being able to speak another language beside English is almost always linked with more chances finding a job overseas.

But that’s not all! Some studies state that bilingualism can positively affect executive functions, i.e. those skills that come into play in situations where the use of routine skills is not sufficient for their success (inhibition, flexibility, planning, working memory, attention and cognitive fluency).

There are some other studies which appear to show that bilingualism may have a protective effect on cognitive function and actually delay cognitive aging, and the onset of Alzheimer’s in old age.

It is also possible that bilingual children have a stronger and earlier awareness that others can see things from a different point of view than their own.

This comes from the constantly adapting the choice of language to the person with whom the child speaks, thus developing a greater awareness of the other and stronger mental flexibility.

Moreover, some languages have words and concepts that others don’t. This means people with two sets of vocabulary see the world in a much broader way.

But does bilingualism cause language delay?


Do children exposed to two languages from birth speak later than others?

Does speaking two languages ​​with children confuse them?

Do children have a hard time learning new words if they hear them in two different languages?

Actually, No.

The language development of bilingual children follows the same stages as the language development of monolingual children.

Bilingualism does not cause language delay

Bilingual babies begin producing their first vocalizations between 3 and 6 months, the first words at 12 to 18 months, and begin combining two words to form sentences between 18 and 24 months, just like their monolingual peers (you can see the stages of language development here).

So why is it so common to hear that bilingualism causes language delay?

The reason is that language development may sometimes seem delayed because a child’s language ability is divided into two languages.

Let’s take vocabulary as an example: if we measure the number of words that a bilingual child is able to use separately, one language at a time, it could turn out that the child knows fewer words than a monolingual peer.

However, if you count the words that the child knows in both languages, the number of words is similar, indeed it could even be higher.

For example, if a child who speaks only English is able to say 50 words at 18 months, a child of the same age who speaks English and Dutch could say 30 words in English and 30 in Dutch.

If you compare the number of words that the two children use in English, it might seem that the bilingual child knows less (50 > 30).

But if we take into account the bilingual child’s entire vocabulary, we can see that he actually knows more (50 < 60). 

Of course, the development of vocabulary in a language is closely associated with the exposure that the child has received in that language.

Stimulation also affects grammar: bilingual children may be less accurate in grammar than a monolingual child.

This also depends on how well the child has listened to that language.

Hence, the language development of a bilingual child follows the same steps as a child growing up in a monolingual family.

This does not mean that bilingual children cannot be affected by language disorder or delay, only that the incidence and probability of a language impairment is the same in bilingual and monolingual children.

How do I know if my child (my student / my patient) should have a language assessment?

Red flags that may indicate language delay / disturbance are:

  • If the child has not yet said their first words (in either language) at 18 months

  • If the child does not use at least 50 words (total) at 2 years old

  • If the child does not start combining two words to form sentences at 2.5 years old (like “more milk”)

  • If the child does not speak in sentences around the age of 3.

These red flags should occur in both languages, if they occur in only one language and the other is fine, then we are not talking about language delay or disturbance but linguistic dominance (which in this case is related to exposure).

In the event that these red flags are encountered, it is advisable to contact a speech and language therapist / pathologist who will assess the child’s language, and decide whether an intervention is appropriate or not.

If this post was useful and you liked it, leave me a like and share it with your bilingual friends, speech therapist friends and pediatrician friends.

If you have any questions, please feel free to contact me.

See you soon!


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Sokolova I.V. Influence of Bilinguism on Socio-Cognitive Personality Development. The Education and science journal. 2012;1(8):81-95. (In Russ.)

Genesee, Fred. (2009). Early childhood bilingualism: Perils and possibilities. Journal of Applied Research on Learning. 2.