Does 'Semilingualism' Really Exist? A Deep Dive into the Truth of Early English Education and Home Strategies Backed by Modern Research

"If we send our child to preschool, they'll become 'semilingual,' not mastering either Japanese or English."

For parents considering early English education, there is no phrase more frightening.

But did you know that in the latest linguistic and brain science research, the very concept of 'semilingualism' is being refuted?

There are established principles in a child's language development, and science has explained 'why language delays occur' and 'how they can be prevented.'

In this article, based on the theories of Professor Jim Cummins of the University of Toronto, a leading authority in Second Language Acquisition (SLA), we will neutrally explain the true nature of the 'language barrier' and offer concrete solutions that families in Japan can implement starting today.

1. The Source of the Fear: The Current Status of the Term 'Semilingualism'

First, let's break the spell of this word.

'Semilingualism' is a term coined in the 1960s, but in modern academia, it is criticized as 'lacking scientific evidence' and being a 'misleading and discriminatory term,' and is no longer used.

Latest Research Findings

• MacSwan's Research (2000):

  Concluded that 'a state of semilingualism (a state of lacking proficiency in both languages) does not exist.' A child always possesses competence in at least one language.

• A Correct Understanding of Bilingualism:

  During language development, there may be periods (such as the silent period) where both languages appear temporarily underdeveloped. However, this is part of the growth process as an 'Emergent Bilingual' and not a lack of ability.

Cummins' 'Interdependence Hypothesis'

Professor Jim Cummins of the University of Toronto proposed the 'Dual Iceberg Representation,' which posits that 'the mother tongue (L1) and the second language (L2) are interconnected in the brain.'

• Above the Waterline: Japanese and English appear to be separate.
• Below the Waterline (in the brain): Thinking skills and cognitive abilities (the Common Underlying Proficiency, or CUP) are connected by a common foundation.

In other words, the established scientific consensus is that 'a strong foundation in the mother tongue (in this case, Japanese) leads to higher proficiency in English.' Conversely, neglecting the mother tongue poses the greatest risk.

2. The Parent Trap: The Gap Between BICS and CALP

So, why do some children seem to be 'fluent in English but can't keep up with their studies'?

The reason lies in the confusion between two types of language proficiency.

The Growth Curves of BICS and CALP

Watch Out! The 'Phantom Gap'

After 2-3 years in preschool, a child will start speaking English with fluent pronunciation (BICS is developed).

Parents see this and feel relieved, thinking, 'My child is bilingual now!' But in reality, the 'ability to think deeply (CALP)' has not yet developed.

If support for the home language (Japanese) is stopped at this stage with the belief that 'English alone is enough,' the child may fall into a state of being 'able to converse but unable to read textbooks.' This is the true phenomenon often mislabeled as semilingualism.

3. Risk-Benefit Analysis for Children Living in Japan

'Living in Japan' is actually a powerful advantage in bilingual education.

We've assessed the risks based on different home environments.

Risk-Benefit Table by Home Environment

4. Scientific Strategies for Home: Creating a 'Rich Language' Environment

The steps you can take at home to prevent delays in the home language and raise a true bilingual are simple.

Strategy 1: High-Quality Japanese Input (Rich Language Environment)

It's not just about increasing the 'quantity' of conversation, but enhancing its 'quality.'

Don't: Simple commands or questions like 'Hurry up,' or 'Did you eat?'
Do: Use the home language (Japanese) to ask 'thought-provoking, open-ended questions' such as, 'Why do you think the sky is blue?' or 'What would you do if...?'

Strategy 2: Make Reading Aloud 'Dialogic'

Instead of just reading a book to your child, incorporate Dialogic Reading (interactive reading).

• Parent: "What do you think this bear will do next?"
• Child: "I think he'll eat honey!"
• Parent: "Good idea! Why do you think so?"

  This very interaction strengthens the brain's CALP (thinking skills) in the home language, which in turn boosts reading comprehension in English.

5. Conclusion: The Mother Tongue Sets the Ceiling for English Proficiency

There is no need to hesitate with early English education out of fear of 'semilingualism.'

The latest research shows us a hopeful fact: 'Children from homes that cherish the mother tongue (Japanese) will also excel in English.'

Even if your child attends preschool, it is crucial to have 'rich, quality time in your home language' to build a foundation for their thinking skills. By following this principle, your child can walk the path to bilingualism in the advantageous environment of Japan while avoiding the risks.

Bilingual Education & School Advisory Office

'I feel like my child's speech in our home language is delayed...'

'Which is a better fit: an international school or a Japanese school?'

At ELT, consultants with expertise in language acquisition will assess your child's linguistic development (in both Japanese and English) and propose an optimal educational plan.

• Developmental Check: Assessment of the age-appropriate balance of BICS/CALP.
• Home Learning Advice: Specific book recommendations and practical methods for 'reading aloud.'
• Educational Planning: Finding the golden ratio for 'English maintenance' and 'home language support' after preschool graduation.

References

• Cummins, J. (1979). Linguistic interdependence and the educational development of bilingual children.
• MacSwan, J. (2000). The threshold hypothesis, semilingualism, and other contributions to a deficit view of linguistic minorities.
• Nakajima, Kazuko (2016). *Bilingual Education Methods (Fully Revised Edition)*. Alc.