Speak Volumes: 12 years from now, what will a bilingual immersion education be?

“Why has no one ever asked me what language I speak at home?” How long do language memories last? For Marcelle van Leenen, Keystone Academy’s Head of Primary School (PS), it traces back to a classroom moment — when a child’s mother tongue is quietly set aside, and an unspoken loss takes root.

Years later, standing at the front of her own classroom, Marcelle began to understand what it truly means to respect, see, and affirm students’ home languages.

She came to see that language is more than a tool for communication. Not only does it form the ground where thinking grows, but it also carries identity: where one comes from, who a person is, and so forth. This shaped her questions as both an educator and a parent: Is bilingualism something we acquire naturally, or something we deliberately design? How can academic bilingualism move beyond utility and become a space where thinking and identity develop together?

In September 2025, Ms. van Leenen joined Keystone to lead its primary school division. Born in the United Kingdom with a Dutch heritage, she grew up in international settings and has worked in education for over 27 years, including in International Baccalaureate (IB) schools across the Netherlands, China, Vietnam, Qatar, Cambodia, Latvia, and, most recently, as headmistress of Windhoek International School in Namibia.

Her upbringing developed deep connections with diverse school communities. The childhood experience of her mother tongue being “not rejected, but ignored” stayed and shaped her reflections on language and identity.

That lived understanding helped her recognize something familiar when she encountered Keystone: a new world school rooted in China, embracing the world. Its bilingual education is grounded in seeing and accepting students as they are. At Keystone, teaching is not just about language acquisition, but about nurturing whole people. The curriculum is not only about knowledge, but about the shared growth of cultural identity and critical thinking.

Since its founding, Keystone educators have built a bilingual immersion system as one of its three keystones, moving beyond surface fluency toward deeper identity development and cognitive growth.

Keystone’s cohort that entered 12 years ago and completed the Keystone curriculum is about to graduate. At this milestone, we reflect on our bilingual journey and ask new questions: In a world of accelerating change, what kinds of learners are we shaping? When language becomes a bridge rather than a boundary, how might education open into something broader and more lasting?

This deep-dive article draws on Ms. van Leenen’s reflections from her daily work and observations, which she shares during morning coffee meetings, parent newsletters, write ups, and, more recently, at various speaking engagements and meetings with the PS leadership team.

Through these ideas, we share Keystone’s ongoing commitments and innovations in bilingual immersion education.

What is “bilingual immersion learning”?

Over time, bilingual education has taken many forms. Some models move students from their mother tongue to English (i.e., the “transition” model); others develop both languages in parallel (i.e., the “maintenance” model. Both reflect respect for learners’ cultural roots and cognitive starting points.

Yet in many programs, the second language remains a separate subject, disconnected from academic learning. This is a gap that runs counter to Keystone’s vision, as the school’s goal is not to train skilled “translators”, but to develop global citizens grounded in Chinese culture, equipped with global perspectives, and capable of bilingual thinking.

From the start, Keystone has clearly defined the use of the second language not as content, but as a medium for learning. Students naturally acquire and begin mastering language in real academic contexts and meaningful, practical applications.

Keystone also aims to nurture both languages as children’s mother tongues. While near-native bilingualism is not always realistic at the primary school level, the school’s commitment is to make the additional language feel as close as possible to a mother tongue, presenting a bilingual landscape that is culturally grounded, emotionally resonant, and intellectually alive.

This philosophy shapes a comprehensive system of immersive bilingual learning across subjects.

At Keystone, language learning no longer belongs only to Chinese or English classes. “Every teacher is a language teacher,” embedding language development within subject instruction during key developmental years.

For example, in English mathematics classes, students learn not only concepts but also academic mathematical language. Similarly, Chinese and English drama courses develop students’ performance skills and expressive language, using movement and role-play to deepen their understanding of character and meaning.

Does learning the same subject in two languages mean repetition?

Even now, Sydney Zhang, who has now spent eleven years at Keystone, remembers asking her second-grade teachers: “If we’ve already learned math in Chinese, why not just memorize the English terms and solve the problems? Wouldn’t that be faster?”

Later, during summer school abroad and while preparing for the SAT, Sydney discovered the limits of that logic. When problems involved dollar conversions or miles and feet, formulas alone weren’t enough. Without cultural context, familiar concepts became unfamiliar.

In one sharing session, she reflected:

Bilingual education taught me how to understand problems and find solutions across contexts. This isn’t just for a particular exam. Chemistry isn’t only about balancing equations, and math isn’t just about competition medals. For me, science should serve life: designing safer bridges for children in mountainous areas, or finding ways to reduce pollution. These problems don’t come labeled ‘Chinese’ or ‘English.’ Being able to shift perspectives and use the right language and thinking in each situation. And that’s what bilingual learning really means.

Dr. Rae Yang, Keystone’s Assistant Head of School for School Affairs, describes this process through a metaphor: building a “scaffolding” of knowledge.

“Students learn concepts through the Chinese system, then examine them through the English system. The two perspectives reinforce each other, helping students form knowledge that is more solid, multidimensional, and transferable,” Dr. Yang said.

In mathematics, for example, students study the subject in the Chinese National Curriculum and in English math through an international framework. This is not duplication. Chinese math emphasizes logical rigor and computational precision, building strong foundations in abstraction and symbolic reasoning. English math foregrounds multiple representations, real-world modeling, and critical argumentation.

The goal of learning in two languages is not memorization, but using language as a prism to examine knowledge from different angles. The real challenge is preventing Chinese and English instruction from becoming parallel tracks that never meet. At Keystone, this begins with collaborative planning between Chinese and English teaching teams, who jointly determine content, set literacy development goals, design teaching and instruction models, and analyze student learning outcomes. Only then does bilingual education move from parallel delivery to true integration.

In the primary school, Ms. van Leenen ensures teachers meet weekly to discuss shared questions and challenges. As she puts it, “Teachers are always thinking about how to do better. But if they stay confined to their own classrooms, it’s difficult to gain new ideas for improvement. Therefore, participating in a broader community, creating together, and inspiring each other is crucial.”

When teachers collaborate deeply, students learn to see the two languages as partners, not competitors. This relationship sits at the core of bilingual education.

At Keystone, bilingual learning is not “half a day in Chinese, half a day in English,” but a unified experience in which students encounter multiple dimensions of the same ideas, rather than two separate bodies of knowledge.

Over time, students develop dual cognitive frameworks. When discussing a concept, they can think and express themselves in both languages without relying on translation. Though difficult to measure in the short term, years of practice show that strong language literacy emerges naturally from this approach.

Learning a language vs. learning through language?

When discussing bilingual curriculum design, Ms. van Leenen often asks: “Do we view language as a separate subject, or as an integral part of our lives?” Questions like “Was this lesson designed to teach language?” reflect a divide Keystone aims to move beyond.

Language is not separate from learning, but itself is a core of the curriculum. Students cannot acquire knowledge, collaborate, or think without it. In bilingual settings, they must draw on both languages to make sense of the world. And this, at its core, is also a project of identity.

Traditional models often treat the second language as a tool layered on top of content, leading to fragmentation. For example, adults watching English stand-up comedy with students may laugh while the students don’t. On the other hand, students may be deeply moved by a text in Chinese but fail to connect when that piece is translated into English. Similar gaps emerge when humor, emotion, and meaning fail to transfer across languages.

This limitation shapes Keystone’s approach. Teachers do not prioritize grammar structures or isolated language drills. Instead, they drive learning through concepts.

For instance, when students explore “ecosystems”, teachers focus on ideas like interdependence and mutual influence. Students naturally think about how plants, animals, and environments interconnect. As questions arise, teachers provide the vocabulary needed to express them. Once conceptual understanding forms, teachers extend, supplement, and refine students’ knowledge. Like the metaphor of weaving cloth, students gather fragments and stitch them into coherent meaning, avoiding the trap of “having full pockets but not knowing how to use what’s inside.”

Here, teachers are not simply transmitters of knowledge, but designers of learning experiences. This reflects linguist Stephen Krashen’s idea of the “language input hypothesis”: students acquire language not through drills, but through rich, meaningful engagement with ideas.

Children learn best through relevance and context, not by memorizing vocabulary first and applying it later. In this environment, language emerges naturally from thinking.

As Ms. van Leenen notes, “If we only focus on how many words a child has mastered and how long an essay they can write, we may be missing the most valuable part of bilingual education.”

When language, cognition, knowledge, and subject understanding develop together, students gain more than bilingual skills. They develop a way of thinking that allows them to understand concepts, analyze problems, and express ideas across languages and contexts.

This integration makes bilingual learning deeper, more authentic, and more enduring.

How do students move from social language to academic language?

University of Toronto linguist Jim Cummins distinguishes between two types of language proficiency: Basic Interpersonal Communicative Skills (BICS) and Cognitive Academic Language Proficiency (CALP).

• BICS refers to everyday communication: greetings such as ni hao (你好, “Hello”), casual conversations, and situational exchanges, such as ordering food or asking about someone’s weekend. These skills are highly contextual and usually develop within one to two years of learning a new language.

• By contrast, CALP is the language of classrooms and academic thinking. It is more abstract, less dependent on immediate context, and typically takes five to seven years to develop in a second language.

Keystone Assistant Head of PS Grace Wang illustrates the shift between BICS and CALP. During experiments, children might say, “Put this in,” which reflects social language. Later, when reviewing, they say, “We tried to make the paperclip float,” moving toward academic language. Eventually, in scientific reports, they use precise and formal disciplinary language.

Oral communication serves as the bridge to academic language. Schools must intentionally teach students how to argue, question, explain, and cite evidence in both Chinese and English.

Keystone’s approach is not to let English replace or overshadow Chinese, but to develop both in parallel and in dialogue. Chinese not only carries emotion, culture, and identity, but it should also be developed to an advanced academic level. On the other hand, English must move beyond everyday fluency toward academic rigor. The goal is convergence: strong bilingual literacy at the highest level.

Balancing academic language and the mother tongue

UNESCO has long emphasized the importance of mother-tongue education as central to inclusive, high-quality learning and cultural preservation.

Ms. van Leenen’s two children both completed the IB program, which values inquiry, critical thinking, and global citizenship. Yet, like many multilingual, transnational families, her children experienced an unintended shift: over time, English became dominant, not because other languages were discouraged, but because the education system at the time failed to support the development of multilingualism.

Eventually, English became both the children’s social and academic language.

This experience led Ms. van Leenen to a hard-earned insight: if bilingualism is not actively nurtured, the dominant language will take over.

When a child gradually loses their mother tongue, they lose more than vocabulary. They lose access to culture, history, a sense of belonging, and a worldview. Language is not just a system of words but a carrier of memory, values, and identity. When a language fades from a child’s life, parts of that identity blur.

Schools, therefore, have a responsibility to recognize, protect, and strengthen students’ mother tongues. When children feel their language and identity are valued, their motivation to learn deepens.

The deeper purpose of bilingual education is to help children develop a strong sense of self and identity. This is why Keystone emphasizes being “rooted in China”: a solid mother tongue is the foundation that enables a second language to reach advanced academic levels.

What is a more vibrant understanding of language literacy?

To understand “language literacy,” we need to look beyond its traditional definition as the ability to read and write. In international linguistics and education research, literacy has evolved into a broader concept shaped by social and cultural practice.

Sociolinguist James Paul Gee, in Social Linguistics and Literacies, introduced the idea of “multiliteracies,” emphasizing not only the interpretation and creation of multimodal texts, but also critical thinking and social participation.

Because the Chinese translation 读写能力 (reading and writing ability) often narrows literacy to technical skills, Keystone uses 语言素养 (language literacy) to capture a fuller meaning: language as cognition, interaction, and identity-building, not just a tool, but a way of making sense of the world.

Public understandings of literacy remain limited, yet how educators define it shapes curriculum, teaching, and assessment, and ultimately our fundamental understanding and value of bilingual education itself.

At Keystone, bilingual development means more than fluency. It means deep reading, or the ability to connect emotionally and intellectually with texts across languages.

Language literacy, as Keystone defines it, includes reading and writing, but also interpreting, expressing, debating, imagining, and creating meaning across contexts, modes, and languages—in everyday life and academic learning alike.

When we talk about bilingual growth, we are really talking about how children learn to think deeply (i.e., deeper learning) and communicate effectively across modes, contexts, and languages.

What can parents do to support bilingual development?

Educational thinker John Dewey once wrote, “Education is not preparation for life; education is life itself.” Bilingual learning, too, should unfold naturally within children’s lived experiences, and not as a separate skill set.

“Involving parents in the learning journey is something we have always strived for,” Ms. van Leenen says. Since becoming Keystone’s Head of PS, she has emphasized open, real-time communication through weekly newsletters, the Toddle platform, and morning coffee meetings. These channels help parents understand learning goals and student progress, and make assessment an ongoing, shared process.

In primary school, she believes, holistic growth begins with relationships. Teachers must intentionally build classroom communities where every child feels seen, safe, and willing to take risks.

At home, parents are both co-builders and guardians of cultural identity. As Ms. van Leenen emphasizes, strong mother-tongue development is the core of language learning. Through meaningful conversations and shared reading, families strengthen children’s sense of belonging while laying cognitive foundations for English learning. A solid first language supports metalinguistic awareness, which transfers directly to additional languages.

Home–school partnership is essential to bilingual success. Keystone encourages families to prioritize the mother tongue. Research consistently shows that strong first-language literacy supports second-language achievement. Long-term studies of Canadian French immersion programs, for example, found that students with strong home-language reading skills performed better academically in their second language (Genesee, 2004), supporting the “common underlying competence” hypothesis, i.e., the cognitive and academic abilities cultivated by the mother tongue can positively transfer to the learning of other languages.

Creating a rich language environment at home matters. Through daily conversations, shared reading, and natural interactions, parents strengthen cultural identity while giving children authentic contexts to use language. Keystone encourages parents to move from being “teaching supervisors” to “learning partners,” exploring the richness of bilingualism alongside their children.

Rather than focusing on spelling lists or word counts, parents might look instead at whether children are eager to express ideas, ask questions, and switch comfortably between languages. This willingness signals healthy language development. Assessment, too, should emphasize meaning-making and intercultural communication.

Every family carries cultural memory and heritage. Children should draw from their home language’s literature and history while also using English in real contexts, such as researching science topics, sharing international experiences, or navigating daily life. This balance helps build confident, grounded bicultural identities.

“If I could only give one piece of advice, it would be: nurture your child’s curiosity about language and see school as a place to learn and collaborate with educators,” Ms. van Leenen shared.

“Because schools can help you understand how children write language and what the key to language learning is. You are welcome to join this exploration.”

What kind of person does bilingual education aim to cultivate?

Wittgenstein once wrote, “The limits of my language mean the limits of my world.” At Keystone, bilingual education is never just about speaking two languages, but about feeling, thinking, and creating in two languages with resonance in reading, clarity in writing, empathy in listening, and the ability to understand ideas across contexts.

At Keystone, bilingual education aims to cultivate future creators:

Our graduates will possess the intellectual, cultural, and ecological fluency to navigate gracefully the colleges, careers, and communities of their choice. They will know how to apply their emotional intelligence, character, and zest for learning to help develop and improve the communities in which they live.

As Ms. Wang often explains, bilingualism does not mean perfect symmetry between two languages. Rather, early immersion helps children develop emotional and cultural connections to a second language that resemble those of a mother tongue.

Research on critical periods in language acquisition supports this. Neuroscience studies also show that early bilingual learners demonstrate stronger neural connectivity and greater gray matter density in regions linked to language processing (such as Broca’s and Wernicke’s areas). In other words, bilingual learning shapes not only competence, but the brain’s language architecture itself.

Keystone’s hope is to give students a foundation for life, to help them understand themselves while engaging with the world; to stay curious about difference while rooted in identity and having a global perspective; to belong deeply and reach widely.

Education’s meaning often lies in quiet shifts: replacing unease with curiosity in unfamiliar settings; meeting other cultures not with defensiveness, but with openness and attention. This openness does not require giving up who you are. It means situating yourself within something larger.

Students do not have to choose between “Chinese identity” and “global citizenship”. They learn to integrate both into a grounded, confident way of being.

As Ms. van Leenen once said, “When we nurture children in two languages, we give them not just access to the world but the ability to shape it.”

At the Grade 5 graduation ceremony, Ms. Wang told students preparing for middle school: “Stay curious and always know where you’re headed. When I retire, I hope to live in a better world you’ve created.”

Twelve years ago, Keystone planted a seed called immersive bilingual education. Today, it stands as a tree that is deeply rooted in cultural soil, with branches reaching outward to the world.

Keystone doesn’t draw lines between language and culture, but builds bridges across invisible boundaries, helping young people find their own coordinates.

Education is not about providing standard answers, but about helping individuals recognize their own voice while understanding complexity, and remain fully themselves while embracing difference.