In this guide
What bilingual and immersion actually mean
A bilingual school delivers content in two languages by design, usually with roughly equal time and depth in each language, taught by teachers who hold both languages. A typical European bilingual school will teach mathematics and science in English while teaching humanities and the arts in the host language, with the language balance shifting between primary and secondary. The aim is that the child achieves academic fluency in both languages by the end of secondary, with university options open in either language.
An immersion school delivers content predominantly in the host country language, with the expectation that the child acquires that language by being surrounded by it across the school day. The English-language input is delivered as a single subject lesson, often with native-speaker teachers, but does not function as a medium of instruction in other subjects. Immersion schools include local public schools in many European countries, as well as fee-charging schools that select an immersion model intentionally.
There is also a third model, partial immersion, that sits between the two. Roughly 70 per cent of the day is delivered in the host language; the remaining 30 per cent is in English. This is more common in Asian markets, where Mandarin or Cantonese immersion schools layer in significant English provision rather than running pure immersion. For the broader frame on bilingual provision, see our piece on best bilingual international schools.
Side by side comparison
| Bilingual school | Immersion school | |
|---|---|---|
| Language balance | Roughly 50/50 across the curriculum | 80 to 100 per cent host language; English as a single subject |
| Teacher staffing | Often two teachers per cohort; one per language | Predominantly host country teachers |
| Curriculum | Bicultural; often a hybrid of host country and international | Host country national curriculum |
| Language outcome by age 18 | Strong academic fluency in both languages | Near-native host language; English at a strong second-language level |
| Best for English-speaking expat children | Families wanting both languages preserved equally | Families committed to deep host country integration |
| Best for heritage-language children | Families preserving a minority language alongside English | Families willing to let heritage language develop at home |
| Academic load | Higher; the child carries two academic vocabularies | Standard host country load; English layered on top |
| Mobility friendly | Moderate; bilingual schools exist in major cities | Lower; the host language acquired does not transfer to other countries |
| Cost | Higher; bilingual provision is expensive to staff | Lower if state-funded; comparable to other private if fee-charging |
| University destinations | Strong in both linguistic spheres | Strongest in host country; conversions needed elsewhere |
Language outcomes in each model
The two models produce different language profiles by school leaving age. A child completing a credible bilingual programme from age 4 to 18 will typically reach academic fluency in both languages. That means writing analytical essays at A Level or equivalent standard in both languages, understanding subject-specific vocabulary in both, and shifting between them without noticeable code-switching difficulty. The outcome is rare but achievable when the school is genuinely bilingual rather than nominally so, and when the home language environment supports both.
A child completing an immersion programme typically reaches near-native fluency in the host language, comparable to a child born and educated entirely in the host country. The English outcome depends on the home environment. A child of English-speaking parents will retain strong conversational English but may lag behind native-speaker peers in academic English by the time they reach upper secondary, particularly in writing and in advanced vocabulary. Schools that handle this well introduce structured English from primary upwards and ensure the child reaches Cambridge Advanced or equivalent English certification by Year 12.
Find bilingual and immersion schools in your host city
Our school finder maps both models in the cities where most expat families land. Free, parent-first, no commitment.
Academic outcomes
Both models produce strong academic outcomes when delivered well. The research literature on bilingual education, mostly from Canada and Belgium, is clear that bilingual instruction does not depress academic performance and may modestly improve cognitive flexibility and executive function. Bilingual children sometimes lag native-monolingual peers in reading attainment in either language by a small margin in primary, then catch up by Year 7. By upper secondary the gap typically disappears.
Immersion children, by contrast, tend to outperform on host language metrics by upper secondary because they have spent more total time in the language. The deeper academic vocabulary in the host language gives them an edge in subjects taught in that language. Their English vocabulary will be narrower than a child schooled in English, and that gap requires deliberate work to close if the child intends to apply to English-language universities.
For the related question of which curriculum the school delivers within either model, see our pieces on the bilingual curriculum and the broader curriculum hub. Curriculum and language model interact; the same family may face two distinct decisions.
Identity, integration and the heritage language
The non-academic dimension is harder to measure but matters more for some families. A child in a bilingual school typically retains a strong English-speaking identity alongside the host language identity. The peer group is mixed. Code-switching is normal. The family's home language has institutional backing at school. This produces children who are comfortable in both linguistic worlds.
A child in an immersion school typically integrates more deeply into the host country culture. Their peer group is local. Their primary social language is the host language. They often identify culturally with the host country in ways that surprise English-speaking parents. This deep integration is a feature for families committed to a long stay or to permanent settlement. It can be a friction for families who expect to move again and who want the child to retain a strong English-speaking cultural anchor.
The heritage language question complicates the picture for families whose home language is neither English nor the host language. A child with a Polish-speaking parent in Madrid, attending a Spanish immersion school, can lose Polish unless the family invests deliberately in maintaining it. The same family in a Spanish-English bilingual school faces the same Polish question with one less major language at home. Heritage language maintenance is parent work; school choice can help or hinder but does not solve.
Cost and accessibility
Immersion schools include the host country's state schools, where these are open to expat children and where the family is committed to the language demand. State immersion is free or nearly so. Private immersion schools, where they exist, charge fees comparable to other private day schools in the city, typically EUR 12,000 to EUR 22,000 annually.
Bilingual schools are more expensive to deliver and the fee structure reflects it. A credible bilingual school in a major European city charges EUR 18,000 to EUR 28,000 annually, occasionally more for the most established schools. The fee premium reflects the dual teacher staffing model, the additional curriculum coordination and the smaller class sizes that bilingual delivery typically requires.
For city-by-city detail on fee ranges, see our fee comparison tool, which separates immersion, bilingual and full international school options where the data is available.
The Asian market: Mandarin and Cantonese immersion
The bilingual versus immersion question takes a particular shape in East Asia, where Mandarin and Cantonese carry strategic family value alongside academic value. Singapore, Hong Kong and a growing band of bilingual programmes in mainland China offer English-Mandarin bilingual streams that aim for academic literacy in both languages by the end of secondary. Schools such as the Singapore American School's Chinese stream, Harrow Hong Kong's bilingual primary and a handful of bilingual independents in Shanghai, Beijing and Shenzhen deliver this at scale.
The pedagogical challenge in this market is sharper than in Europe. Mandarin literacy demands roughly twice the time investment of an alphabetic-language literacy because of the character system. A genuine Mandarin-English bilingual programme allocates more time to literacy in both languages than a comparable French-English or Spanish-English programme. Schools that pretend to deliver Mandarin literacy at academic level without dedicating that time are not delivering what they claim. Parents touring schools in Asia should ask how many minutes per week of Mandarin literacy instruction the school delivers in lower primary; the credible answer is at least 400 minutes per week, often more.
For families choosing pure Mandarin immersion through a local Chinese-medium school, the language outcome is exceptionally strong but the English outcome depends entirely on home environment and supplementary tuition. The local Chinese system also produces a particular kind of academic identity that some expat families embrace and others find too narrow for an internationally mobile child. The decision is not generic; it is specific to family priorities and stay length. Our city guides for Singapore and Hong Kong set out the school landscape in each market in more detail.
Which to pick if
If you are committed to the host country for ten or more years and value local integration: immersion is usually the stronger choice. The depth of integration into local culture and the near-native host language are durable assets.
If you expect to move countries within five years and want to preserve English alongside the host language: bilingual is the safer choice. Both languages are protected institutionally and the child does not have to rebuild English on the next posting.
If your child has strong language aptitude and you want both languages preserved at academic fluency: bilingual delivers this outcome more reliably than immersion supplemented by tutoring.
If your child has language-based learning difficulties: immersion is risky. A child with a specific language disorder or dyslexia working in a non-native language at academic level is carrying a double load. Bilingual settings are more accommodating, but the question deserves a specialist assessment. See our piece on SEN at international schools for the wider context.
If you value cultural breadth and a multilingual identity for the child: bilingual schools deliver this more visibly than immersion. The peer group itself models the bilingual identity.
If you value academic ambition in a single language and accept that the second language will sit at a strong second-language level: immersion is usually the academically deeper choice within the host language.
The decision interacts with the wider public versus private school abroad question. Immersion is often the public school answer in countries where the public system is strong. Bilingual is more often a private school answer. The full comparison, including cost and integration, repays the time spent on it.