The significance of mother tongue language in additional language acquisition
Since 1999 where UNESCO founded International Mother Language Day to promote awareness of language and cultural diversity around the world, this day has been celebrated on 21st February.
What is a child’s mother tongue language?
A child’s mother tongue is the language which the child has spoken for important things in life since birth. In multicultural families, several languages can be spoken, but only rarely has the child an equal command of its two parental languages.
This blog post looks at my own personal experiences and reasons for my choices in relation to my children’s language development when we moved abroad; furthermore it looks at the research supporting my choices for promoting my children’s mother tongue language.
My personal experiences with bringing up bilingual children
Having brought three children to England without them speaking or understanding much if any English despite having had an intensive English course at home prior to our expatriation to London, I consulted an English as an Additional Language (EAL) consultant. We met a few times, and what struck me was her persistently insisting we discuss our plans for further developing our children’s mother tongue. This being Danish.
I later learnt that the thinking behind this approach was that the more proficient a child’s mother tongue becomes, the stronger an additional language becomes as concepts and skills learnt in the mother tongue language are transferable to any additional languages.
As such, the EAL consultant had three pieces of advice for us: Firstly, that we never gave up speaking our own language at home. Secondly, that the better we (we being the parents) became at English, the more we would inspire our children to acquire this new language too. And thirdly, that we watched lots of English children's TV with our children, explaining vocabular and phrases to them.
I have often thought of how fortunate my children are to be bilingual - not only do they have two languages which going through today’s educational system come in handy and will be an advantage in the future job market; they also know another culture inside out and are able to express themselves authentically in both their languages.
Had we skipped Danish, they wouldn’t have been able to remain close to their extended family and their friends in Denmark; and repatriation would have been much more challenging than it proved to be without the added complications of not knowing the language of their roots.
Initially when moving to London, my children didn’t understand anything around them; and without going into the details of this, it was challenging for them all. Very challenging. Gradually, they started picking up things; my youngest would cite TV ads without knowing the meaning of these, and my middle child would come home from school telling us to "tuck in your shirt" (the headmaster of his school greeted the children at the gate every morning checking they were appropriately dressed!).
Being Danish, my children loved to play outside and would go around knocking on a neighbour’s door to ask if their children would come out and play. At first, they would point to their football indicating wanting to play a game. As their language developed, they would simply ask “Football?”, then “Play football?” followed by “You play football?” to approximately half a year into our stay being able to produce full sentences with slang: “Do you fancy playing footie?” There is no describing anyone’s sense of achievement when they were spitting out English like there was no tomorrow.
Travelling and living abroad, I have met several families who had given up speaking Danish with their children. I have never fully come to understand this. To me, regardless of how well you speak another language, most people are emotionally most authentic in their mother tongue. And you would want to be as authentic as possibly with your children, right? Adding to this, it was important for me to make sure that my children could communicate with their family and friends at home. Lastly, I also wanted to make it possible for them to return to Denmark and finish their education.
As such, I was the “mean” mum insisting that we spoke Danish within the household unless we had people visiting who spoke no Danish. I also insisted that my children did daily reading for 20 minutes in Danish on top of their English reading - this wasn’t popular amongst the minor members of the family, but it did make the transition going back to Denmark much easier.
As time went by, we developed this in between language at home where we would speak a mixture of English and Danish. My children would use vocabulary from one language and apply grammatical knowledge of the other language. To outsiders, they might as well have spoken a completely different language, but we understood each other. We also played games like only being allowed to mix words of the English language into Danish if we could spell these - this, we stopped after spending an entire evening learning the sequence of letters in "supercalifragilisticexpialidocious"; but boy, we had fun!
Admittedly, it was hard work for us all; but looking back, it was worth the persistent effort. All my children now read and write equally well in both their languages - at times, it’s been a hard road to travel, but I reckon it’s a gift to treasure for life.
How does a child’s mother tongue affect its acquisition of an additional language?
A mother tongue language is more than just a language; it is also a person’s personal, social and cultural identity. Many of my clients express feeling different in their different languages; seemingly, there is a lack of integration between the selves you develop in your various languages depending on the context of language acquisition. For instance, ways of speaking which may be considered rude in British English, may be perfectly passable in Danish; this means the speaker must adjust their choice of words and language before delivering say a question or a reply. This helps children (and adults) develop empathy for the other party’s perspective and as such enhance communication skills in all their languages.
Studies show that children are taught essentials skills such a critical thinking and literacy skills which are transferable into their additional language(s). This means that things learnt in the mother tongue don’t need to be relearnt in an additional language; as such the mother tongue language can become a resource when learning additional language(s) and in school settings if schooled in a language different from the child’s mother tongue.
The importance of mother tongue
Canadian Professor Jim Cummins states that it takes a child approximately two years to develop native speaker fluency in social settings. Acquiring what Cummins calls academic language and to be working on the same level as native speakers in academic settings, it takes 5-7 years of immersion in the target language; and this only goes for children who are schooled in their host country’s language.
Cummins also found that children who grow up bi- or trilingually, develop a deeper understanding of sentence structure and expression, making learning and using languages easier. Furthermore, children with just one language develop a more fixed mindset on communication and don’t show the same depth of language, nor the same flexibility in their ways of communicating. The last of Cummins's points, which I wish to refer to, is his findings of children with a strong mother tongue finding it easier to learn additional languages - just as our EAL consultant had advised. 
So for all parents to bi-or multilingual children, give your children time and keep speaking your own language at home - your child will have a gift for life and may very well thank you for it later. Happy Mother Language Day!
 https://www.sciencedaily.com/releases/2018/08/180823092018.htm, accessed 8th February 2020
 http://www.lavplu.eu/central/bibliografie/cummins_eng.pdf, accessed 8th February 2020