21 Insightful Tips to Raise a Trilingual Child
Whether you want it or not, the world is becoming more and more globalized and cosmopolitan. The future of science is multidisciplinary. The inclusion and diversity strategies are considered nowadays as vectors of sustainable development of societies and organizations. And where does linguistic diversity stand nowadays? Already in 1979, Ross Werner wrote the “European continent is fundamentally characterized by linguistic diversity”. However, many would agree that in 2020 the multilingualism in the world’s cities is far from being sustainable¹. And where does multilingualism start? Taking into account the cosmopolitan nature of big cities, a large part of it starts with raising a multilingual child born into an international family. And that’s what I wanted to talk about today.
I’m a Russian who has an English-speaking South African husband and we currently live in Germany. Our baby girl was born in early 2020, but even before that, we inevitably ran into the question of how to raise her from the language point of view. Both parents belong professionally to the IT-world, with a research background, and are not professional linguists. Therefore, I started gathering tips from 2 main sources: friends and acquaintances with a multilingual background, and relevant literature. My main filtering criteria were natural rationality and brevity — I needed to start somewhere and not be overwhelmed. After all, this is my first child and there are tons of other topics which also required some investigation, e.g. the birth process, breastfeeding, diaper changing, sleeping, and so on.
What came as a surprise for me, that multilingual families whom I was “interrogating” had basically two approaches. In one case, they exhibited unconcerned complacency under the slogan “You don’t have to do anything special, just wait and everything will happen automatically”. Personally I’m not satisfied with this approach, especially having seen that children grow up silent, and communication is uncomfortable for them. In the other case, parents were saying that they are following the “One person, one language” approach, whereby each parent consistently speaks only one of the two languages to the child. This principle seems to be very reasonable and it has been proven by the experience of many bilingual parents. However, this single recommendation was definitely not enough for me. My mind was throwing out a lot of questions, such as: Which language should parents speak between themselves in the presence of their child?, Which language to use in public places with the child, where no one understands the parent’s language?, or How to support a weakening language of the child?.
Luckily, I found an interesting and insightful book by Elena Madden “Our Trilingual Children”² (in Russian). The author is Russian, has an English-speaking American husband, they live in Germany and raise twins. The book is very strongly focused on the author’s personal experience, which in my opinion could be a disadvantage for a wider range of readers. But still, it contains a lot of profound thoughts and tips which provided guidance for my further thinking concerning the multilingual approach for raising a child. I could not find an English translation of the book, but I wanted to summarize the tips that I extracted from this book for myself and for my husband (who does not speak Russian). Additionally, I thought that someone might be in a similar situation to ours, and this list of 21 tips on how to raise a trilingual child, was born. For better orientation, I have divided all the tips into 5 groups, namely: (1) Speaking, (2) Emotions/Health, (3) Culture/Education, (4) Tracking, and (5) Additional Tasks for Parents. I use continuous numbering for all the tips. Some tips are linked, but most are independent of each other, please find them below.
Speaking
It has been proven that babies begin to learn language sounds before they’re even born³. Other research shows that by the time they’re born, newborns can not only tell the difference between their mother’s language and any other language⁴. All the world’s languages put together comprise about 800 sounds⁵. At birth, the baby’s brain can tell the difference between all 800 sounds. However, this ability declines substantially by the 12 months of age.
English-learning infants easily distinguish Hindi and Salish sounds at 6 months of age, but this ability declines substantially by 12 months of age. English-learning infants at 12 months have difficulty in distinguishing between sounds that are not used in English⁵.
Therefore, speaking, the most common ways of exposing a child to a language is one of the most important aspect of language learning for babies starting from the very birth. In this section, I summarized the tips on how to raise a multilingual child from the perspective of speaking. This perspective includes advice on the parent’s communication with their children and between themselves, and on children’s communication with their peers.
1. Adhere strictly to the principle “One parent — one language”.
The “One person, one language” approach is a popular method for raising multilingual children. According to this approach, each parent should consistently speak only their native language to the child. The theory behind the approach is that by separating the languages from the beginning, parents can prevent confusion for their bilingual children. Invented more than 100 years ago, this method is still considered as a cornerstone to the multilingual raising of children.
An important note on sticking to the “one person, one language” principle. It might happen that “friendly” daycare workers or other uninformed locals recommend that you switch to talking to your baby exclusively in the language of the country where you live in, both at home and outside. Madden gives vivid examples of such recommendations given to her by the locals². However, as she points out, a great downside of this action is that if parents stop talking to their child in their own languages, it is difficult to get back to speaking in the languages of parents. Children desperately resist each change of language. Therefore, it is important to bear in mind that the “one person, one language” principle works the best if followed strictly.
However, as explained above, the “one person, one language” principle does not cover all the practicalities of daily communication with multilingual children, and the rest of the tips are aimed at better understanding and dealing with these practicalities. Thereby, all tips imply that parents adopt the “one person, one language” as the ground principle.
2. Correct speech mistakes of your child outside of the communication situations.
The question “To correct or not?” is quite “global”. How do you feel about children’s mistakes? And for dads and moms of multilingual children, it is additionally important to know what to do when the child mixes languages, for example, mixed pronunciation, words, meanings or speech constructions in different languages.
Some sources say that if you criticize a child’s speech all the time, they might develop some certain communication insecurities⁶. This reminds us that “growth errors” are inevitable (in the same way that falls, bruises and scratches are inevitable when a child learns to run or ride a bicycle). Any parent will acknowledge the validity of these comments. However, some doubts are inevitable here. Is it reasonable to completely ignore speech mistakes or even treat them as achievements?
As Madden points out, for a foreign parent in Germany such doubts are particularly strong. Even the “tolerant” Montanari admits that in monolingual Germany, the population expects foreigners and their children not just to know the language, but to speak good, clean and correct German (even though “clean” German is allowed to include international words like pizza)⁷. Montanari generally recommends explaining the rules to the child if the speech error persists.
Personally, I like the compromise approach of Madden who recommends not to correct the child’s mistakes directly in the moment of communication, but rather outside of the situation. For example, if your child makes a speech mistake while asking you a question, provide the answer, discuss what’s important for the child, and later discuss the mistake. This doesn’t imply ignoring the speech mistakes, but rather postponing the corrections and maybe even dedicating a “special time” for them.
3. Each parent should speak his or her language with the child everywhere (e.g. playground, in the street, shops, etc.), even in the presence of the locals who speak other languages.
This advice stems from the recommendations of E. Montanari⁷ and C. Baker⁸. The authors do recommend not to switch from speaking your own language with the child to speaking the language of the society where you live in, even in the presence of the locals. Otherwise, the child might have an impression that the mother’s or father’s language is not “prestigious”, and the parents might even be ashamed of their languages. Over time, this discovery might lead to the situations when children themselves could be ashamed of the “concealed” language which is not worth demonstrating. And consequently even of the parents who speak that “concealed” language.
At the same time, as Madden wisely points out, some members of society, unfortunately, don’t always exhibit much tolerance towards immigrants speaking their own languages. Therefore, she advises to always speak with your child in your own language but to also relay the communication to the present locals in their language, if the communication is relevant to them, or if it is clear that the language detachment is especially unpleasant for the local.
4. If both parents are non-native speakers in the country where they live, it might NOT be the best idea to speak between themselves in the language of that country.
Provide that parents adhere to the principle “one parent — one language” (see Tip 1 above), a question can arise: which language should the parents speak among themselves, in the presence of their child? This question is particularly essential if both parents can theoretically speak the language of the country where they live in, but they are non-native speakers.
Russian-speaking Madden and her English-speaking husband, who live in Germany, speak English to their children². However, Madden shares that initially, they were speaking among themselves in the language of the country where they lived — in German.
“Stupid situations were arising since German is the third language in the family. For example, I am busy and I can’t give a peach to Alek, so I suggest him to go to his father and ask for it (I demonstrate in Russian how to do it — maybe I am doing a mistake?). Alek runs and asks his father to give him a “Persik” (Russian for peach). The father does not understand — I have to shout from another room in German that the child wants “einen Pfirsisch” (German for peach). The father understands and asks Alek: “Do you want a peach?” What kind of confusion should it cause in the child’s brain?…” (E. Madden, “Our Trilingual Children”²)
The literature review shows that up to now it is not clear whether children are able to embrace statements that are not addressed directly to them; some evidence confirms this, some does not. In any case, the experience of Madden’s family shows that after the children went to kindergarten at the age of two, the German language became disproportionately strong for their children, which opposed the parent’s desire to have balanced multilingualism. That’s why they started with a new approach where the father always spoke in English, and the mother always spoke in Russian with their children. Thereby, the parents to an approach, whereby they discuss the “adult” topics, without the presence of the children, in German. An additional benefit of such an approach is that time with the children is focused on the children and not on “adult” topics.
Another approach is to choose the language, spoken between both parents, as the language that needs additional support (provided, of course, that the language is comfortable for you and your partner). For example, my husband and I speak English between ourselves. The reason for this is that it is (1) the most comfortable language for us and has always been our “relationship” language, and (2) it will most likely be the “weaker” language for our daughter since we plan for her to attend a bilingual German-Russian kindergarten.
5. Ensure communication with native speakers of the “minority language”, especially with the same-age peers.
The child should understand that even if one of the family languages is not spoken widely in the country where the family lives, it is still a proper means of communication. To achieve this understanding, it is the task of parents to ensure that their child communicates with native speakers of that language. It is a great idea is to organize a trip to a country where the majority of the population speaks this language, to arrange permanent communication with relatives in that language, or to find local communities where children of the same age communicate in that language.
6. Be prepared that if you have several children, they are likely to eventually start talking among themselves exclusively in the language of the country where you live in.
In her book, Madden describes the situation which happened to her twin Russian-English-speaking children sometime after they went to a German kindergarten, around the age of two years old. The German language became the very “strong” one for the kids, and eventually, they started using it between themselves, even at home. The author shares that this contributed towards the creation of a kind of “subculture” within their family. That is an important factor you might want to consider when analyzing which of the languages of your family needs additional support. You can even take this into account when planning another baby :)
Emotions / Health
An essential component of any parenting approach is promoting emotional as well as physical health. This component is inseparably connected to language development. For example, the acquisition and development of the child’s language(-s) is normally observed by health professionals in child health surveillance, in addition to the characteristics of neuropsychomotor development⁹. In the chapter below I address this important perspective of parenting by presenting the tips which lie at the intersection of emotional and physical health and the multilingual language development of children.
7. Monitor your child’s physical and mental health.
This is a piece of generic advice for any parents since only with the fulfillment of this prerequisite, can the language development be successful. For example, illness can affect hearing which, in turn, will cause problems with understanding spoken language. Hearing problems can, in turn, affect speech development. Children who are ill also lack the enthusiasm to speak and communicate in a non-verbal manner. This can hinder the development of language and communication. In addition to illness, physical development can influence language. Vocal cords and speech-related facial muscles must be developed in order for a child to orally communicate effectively. Fine motor skills are also necessary to write or draw letters and symbols¹⁰.
The most general advice for parents of multilingual children is is to make sure that the communication, in whichever language, does not turn into stress, but is a pleasure for your child².
8. Consider the child’s personality, his or her psychophysiological characteristics, also gender, temperament, character, abilities and preferences.
Considering the psychophysiological characteristics of your child can contribute to his or her language development.
For example, kinesthetic children will gladly learn the language by playing with different substances.
Alec at the age of 4 years and 4 moths asked us for explanations after he was given the opportunity to weigh the sand, measure the length of the shoe or determine the volume of fluid. (E. Madden, “Our Trilingual Children”²)
Another example is taking into account the temperament of a child.“ Restless” children, who have too much energy for “book” games, are able to perform any task if you present it as some game involving movement.²
Oddly enough, gender has been known to play a role in a child’s language development. Around the age of two, girls tend to start developing language at a faster rate than boys. They begin to communicate more fluently, and understanding of the spoken language develops quicker¹⁰.
9. Make sure the baby goes through emotions in the language you want to teach to him or her.
Emotions are at the heart of the language learning process. A lot of words that are remembered by children are based on the emotions which the child felt for the first time when experiencing the words². Therefore, to support the development of a language spoken by your child, you might want to create a special environment for them that would ensure that the child experiences emotions in the preferred language. For example, singing can help children express their emotions, like happiness or sadness, through the language of the song. Or you could go with your child to a zoo and learn the names of animals while looking at them.
10. Don’t worry that your child will have several “identities”.
As Madden points out, some people look for symptoms of personality disorder in multilingual children.
In our opinion, the problem of the “three identities” did not arise in our family. Outside observers do attempt to recognize and count them from time to time. I have already heard it in different versions: she is an “American” child, and he is a “Russian” child. As I understand it, this is so because Anja always smiles light-heartedly, and Alexander always has a romantic/tragic/occupying/full of anxiety, etc. expression on his face — one that I understand is perceived as “Russian”. (E. Madden, “Our Trilingual Children”²)
However, thinking about “national character” is an ignorant thing to do. Stepping on this slippery slope can carry one away thinking stereotypically, if not with a jaundiced eye. Personally, I prefer to think of my multilingual and multicultural child as a “citizen of the world”, a term coined by F. Dostoevsky.
Culture / Education
A tremendous part of how children develop is determined by the culture they grow up in. Thereby, language is one of the ways through which culture affects development. The research on adults shows that languages forge how people think and reason. Moreover, the content and focus of what people talk about in their conversations also vary across cultures¹¹. If you want to expose your child to the culture of the country where you grew up, it is important to promote it to your child. In its turn, education is inextricably connected to culture. Culture can impact on the values of education and the way it is organized and taught. Education prepares children for further social integration and cannot be detached from its cultural context.
In order to show what you can do as a parent, this section introduces tips for raising a multilingual child concerning the cultural and educational aspects of a child’s upbringing.
11. Take care of the cultural perspective of multilingualism. Read books in your own language, learn songs, show videos and cartoons. Teach your child to read and write in this language.
Multilingualism opens up distant horizons. Think of it like this: a multilingual child does not only speaks several languages, but he or she belongs to several cultures. However, as Madden puts it, if parents want their languages to be truly native (and not foreign) for their child, the cultural perspective of language education is to be taken into account².
Natural multilingualism differs from early immersion in foreign languages which is now fashionable in Germany, Russia and the rest of the world. Even if a baby is not only exposed to a foreign language during some kind of classes but also the baby reads foreign language books or watches movies in this language, he or she is still likely to learn them “from the outside”. For example, Madden describes a man who only knows his own language and who has never left his country as a “prisoner” of his or her own language and everything behind it, that is, the way of thinking and lifestyle. In contrast, those who travel abroad are fortunate to get a chance to look at the world from different eyes and broaden their own horizons.
Thus, for example, in German, it is necessary to “speed up” for the future action at the beginning of the sentence (ich will, ich werde… — I want, I will…), on the way, to think about the time, reason, image and place of this action — and only then proceed finally to the action itself. In contrast, in Russian, in general, the word order in a sentence does not matter that much, so it does not matter in what order to think and act (“whether to act at all… whether to think at all…” as Madden puts it).
Thus, a rewarding consideration for parents, and the child, is that a multilingual person who masters several languages receives some sort of freedom, because he or she can choose the language, and therefore, the way of thinking. Children’s mindset expands, they can talk about everything they want in the most accurate way. They can choose an appropriate style of communication: rational and “super organized” German or “ad hoc” Russian. Multilingual children always have this “code-switching” at their disposal.
12. Don’t succumb to the temptation to buy adapted editions of books in your own language.
A very short, but important advice provided by Madden, which I really like. Often parents see adapted editions of books in their own language in the book stores, e.g., adapted Russian fairy tales books sold in Germany. Those books can be shortened, with modernized and simple vocabulary. However, more complicated or unfamiliar words, for children, have to be dealt with sooner or later. Thus, Madden recommends introducing these words gradually — and ideally, better before reading.
13. Develop multilingual creativity.
Any child is a creator, each parent would confirm that. However, the creative spark that ignites between languages exists only in multilingual families. Children at a certain point grow up to create their own words, and multilingual children can thereby construct amazing multilingual speech formations.
Here’s a scene from when the kids were 3 years 5 moths old:
Аnya: What is that?
М.: That’s an alarm.
Аnya: О! Noch mehr Larm! (O! More noise! — translated from English)
(E. Madden, “Our Trilingual Children”²)
Phonetic “code-switching” from the example above opened the way for an unintentional verbal game. In this sense, they have a principled ability to build something of their own; something original. Madden recommends to encourage and develop this sort of creativity for multilingual children.
14. Send your child to a bilingual kindergarten.
There are many advantages to sending your child to a bilingual kindergarten. This is a chance to strengthen the “weak” languages of a child, to foster a child’s communication and integrate them into diverse groups, to develop the child’s ability to focus and problem-solve¹².
15. Use any opportunity for communication with your child in your language.
Madden recommends using any occasion and any opportunity to talk and to teach your child something new (in your language). For example, when on the road you can name and discuss birds, trees, you can count oncoming and “passing” cars — red, black, you can even compose fairy tales. Good communication encourages your children to express their feeling and thoughts to you. Communication also allows your child to learn how to listen and respond in a sensitive way. Doing so in the language you want your child to learn will strengthen that language strongly.
Tracking
“You can’t manage what you can’t measure”. W. Deming
This phrase, from an American statistician W. Deming, is often used in businesses for motivating the organisations to measure the key performance indicators. This helps to monitor the company’s progress and improve processes.
Developing some sort of plan and tracking milestones can also be useful for the parents of multilingual children to achieve mindful and efficient upbringing of their offspring. The tips which can help you to manage and control the raising of multilingual children are summarized in this section.
16. Set yourself a goal.
Some parents might not be sure which indicators of their child’s development they should monitor. Madden recommends to ask yourself a question:
What do you really want from your child? Just a bare minimum of a language, that is, that they understand you? That they can speak your language fluently, are able to speak to their relatives? That they know at least one language as their native one? But then which one of the three?
What I personally feel close to is the advice of Madden to have “balanced” multilingualism as a goal. This approach was originally suggested by James Cummins’, according to whom the intellectual development of a child happens only when all languages of a child are developed equally well¹³. In other words, balanced multilingualism is achieved when the child masters not just day-to-day speech of the language, but also a “bookish” way of speaking.
17. Starting from the birth of your child, keep a table showing the extent to which several languages in your family are supported.
Keeping a table showing the support of several languages in the upbringing of your child can help you to identify which languages are “weaker” than the others. If your goal is to reach a balanced development of several languages for your child, this will help you to understand which of languages need additional support at the current moment.
In the table above I present an approximate table which is relevant for our baby, whose parents speak Russian and English and who lives in Germany. For example, in our case, the parents speak English between themselves which is a strong supporter of the English language in the family. Therefore, my husband and I have made a decision to send the child to a German-Russian bilingual kindergarten to support the Russian language, and not to a German-English kindergarten.
18. Record the development of the speech for your children, e.g., with the help of a table where you write down at which month your baby started to pronounce certain sounds, words, and sentences.
It seems that many experts are of the opinion that there are no norms of the language development for children, even for a unilingual child. Some kids start speaking early and correctly, and others only start later. It is also known that several “geniuses” started speaking very late — Newton and Einstein among them. Therefore, even if your baby does not start speaking “early”, don’t rush with the conclusion that something is wrong with the intellectual development of your child.
What could be useful though is to keep the track of your child’s language development in order to know how to help your child to develop. Experts distinguish certain language categories which might be worth tracking when the child masters them: (1) intonated babbling, (2) vocables — the sounds that a child repeats in certain situations, (3) babbling words, (4) holophrasis — statements consisting of one word that replaces the whole sentence. By and large, most children babble at the age from 4 to 6 months, pronounce their first word by 12–13 months, start combining words by the end of the second year, and construct a large number of sentences by the age of 4–5 years¹⁴.
E. Madden emphasizes that these “norms” significantly depend on the language of the child. This can be explained due to the language specifics. For example, in the Russian language, it is possible to express statements in very short phrases whereby the word order does not matter, in contrast to English. Thereby, it might appear that an English-Russian speaking child starts speaking the Russian language correctly “earlier” than English, which would not be really true.
The table above shows a possible way of tracking the development of languages for a multilingual child.
Even though no strict norms of language development exist, recording such a table might help you as a parent to track how balanced is the development of the languages for your child. Should you want to work on a “weaker” language with your child, this table might be used later to reflect the development of the child’s language, e.g., with a speech therapist.
Additional Tasks for Parents
In conclusion, I have gathered several advises of a diverse nature. They can be viewed as additional tasks for those parents who want to become even more familiar in the topic of developing their children’s multilingualism.
19. Read at least several books on the topic of how to raise a multilingual child.
As mentioned above, some parents exhibit some kind of complacency when it comes to choosing and sticking to some principles when raising multilingual children. Such parents hope that things will happen automatically. If you don’t belong to that category of parents and you want to be well informed about proactive ways to develop your child’s multilingualism, then probably the best advice for you would be to read at least several books written by experts in this topic. It goes without saying that reading the relevant literature is very useful since it provides a foundation of knowledge of multilingual upbringing of children — luckily, up to now the world has gathered plenty of experience. It also helps you to place your own thoughts and conclusions within the context of the state-of-the-art pieces dedicated to the topic of the multilingual upbringing of a child.
NB. Those who master Russian can find plenty of references an extensive amount of the corresponding literature in the book of E. Madden². If you know of some other good sources, please share them in the comments to this post!
20. Get inspiration from positive examples of multilingually raised children.
It could be inspiring for you to find and follow some positive examples of raising multilingual children. Of course, social networks can be of huge help. For example, you can find some groups on social networks where parents exchange their experiences on raising multilingual children. Or you could find a profile of a young mom or dad of a multilingual child on Instagram and follow them in order to get some insights on how they raise their children which might be of help to you too.
If you are not into social networks or you have not found your source of inspiration there, you can try to investigate the historical examples of multilingual families who belonged to your culture. Thus, Madden provides an interesting example of how children in the old Russian noble families easily and profoundly learned several languages. In particular, she refers to a spectacular scene showing the “code-switching” from V. Nabokov’s “The Other Shore”, see the quote below.
A father unfolds a German newspaper. When his son asks him some delicate question, he begins to answer it in English. Suddenly, having cut off the explanations, the father switches to French to tell his wife that Tolstoy died — she answers depressingly and quietly in Russian. (From V. Nabokov’s “The Other Shore”)
Why were languages so easily learned and mastered by children in the old noble Russian families? Madden explains it due to the fact that mothers back then could delegate some of the everyday tasks such as child care, upbringing, and education. They “outsourced” these tasks to nannies or governesses, so that the mothers can just play and talk with their children. Such living conditions are, understandably, difficult to reproduce in our times, but modern parents can probably learn a lesson from those families. Particularly that it is important to ease the relationship with the child, to give up constant pressure and endless teachings, “just” love and care, talk, play and laugh together.
21. Parents of multilingual children should not neglect any advice relevant to monolingual children.
The last tip is to apply to your multilingual children the same basics which are recommended to apply with monolingual children. There are many strategies and techniques out there that help children learn, which you can acquire, again from reading the relevant literature, speaking to the other parents, doctors, experts and so on. These basics can be applied to learning any language, and of course, to several languages as in your case as well.
In general, being a parent requires care, love, understanding and the ability to keep your children on the development path. Being a parent of a multilingual child poses additional challenges especially if you do not have ready examples in front of you of how to raise children in a family speaking several languages. In this article, I attempted to divide and conquer the tips for raising multilingual children which I found in the books of E. Madden and some other sources which you can find below.
Thus, I identified 21 tips that I collected into five groups and discussed them in the corresponding context: speaking, emotions and health, culture and education, tracking, and additional tasks for parents. Throughout the text, I mainly provided examples based on the instance of my trilingual family whose members speak Russian, English, and German. However, the tips are generic enough to be applicable for the upbringing of multilingual children who speak any number of different languages.
Lastly, I am not an expert or professional in the matters discussed in this article. Rather, I am a curious mother, with a research background, who summarised my findings for the benefit of myself as well as anyone else who may be interested. If you have any questions or comments for this material or have your own experience on how to raise multilingual children, I’d be happy to hear from you.
Literature
[1]: M. Erard, “The Unsteady Future of the Multilingual City”, 2016
[2]: E. Madden, “Our Trilingual Children”, 2013 (in Russian)
[3]: Hepper et al., “Newborn and fetal response to maternal voice”, 1993
[4]: Moon et al., “Language experienced in utero affects vowel perception after birth: a two-country study”, 2012
[5]: P. Kuhl, “Early language acquisition: cracking the speech code”, 2004
[7]: E. Montanari, “Wie Kinder mehrsprachig aufwachsen: Ein Ratgeber”, 2002
[8]: C. Baker, “A Parent’s and Teachers’ Guide to Bilingualism”, 2000
[9]: Pizolato et al., “Child’s language development surveillance: knowledge and practices among primary health care professionals”, 2016
[12]: https://www.maryelschool.org/the-advantages-of-a-bilingual-kindergarten-education/
[13]: J. Cummins et al., “Bilingual education”, 1997
[14]: D. Shaffer, “Developmental Psychology: Childhood and Adolescence”, 2009
