How English Immersion Drives Children's Academic Success
When parents consider English immersion for their children, the first question is often about the language itself: will they speak fluently, will they lose their accent? But the question that really deserves the conversation is different: how does immersion affect performance across other subjects, a child’s confidence in the classroom, and their approach to challenges? At International School Costa Brava, we have watched the answer unfold for years, and the data backs it up.
This article steps away from the general neuroscience of bilingualism to focus on something very concrete: the measurable effect of immersion on maths, science, reading comprehension and motivation, and what parents can expect to see in their child’s progress, stage by stage.
The essentials, at a glance
Recent studies show that well-designed English immersion improves performance in maths and science, not just in the language itself, and that reading comprehension skills transfer to a child’s home language. Immersed pupils also tend to show greater academic confidence and motivation in class. At ISCB, we support this process with a demanding British curriculum and close monitoring of each child’s progress, stage by stage.
Immersion and maths: a link that surprises many parents
One of the questions families ask most often during admissions interviews is whether learning in English might “take time away” from maths or science. Recent research answers clearly: not only does it not subtract, it adds.
A recent analysis of language immersion programmes in the United States, tracking nearly 5,000 fifth-grade pupils across several school districts, found that 64% of students in immersion programmes reached proficiency in maths, compared with 55.4% of their non-immersion peers. Another large-scale study, focused on pupils in grades 1 through 4, observed gains of 0.12 and 0.14 standard deviations in reading and maths respectively, with improvements visible as early as first grade.
Academic performance in non-language subjects improves because immersion trains exactly the cognitive functions that underpin mathematical reasoning: sustained attention, working memory, and the ability to hold several steps of a problem in mind at once. A child who solves problems across two language systems develops, almost without noticing, more flexible reasoning muscles.
At ISCB, maths and science are taught entirely in English from Primary onwards, within the framework of the British curriculum. It is not an add-on: it is a structural part of how we learn.
Reading comprehension: what is gained in English is not lost elsewhere
Another common concern among families is whether immersion might harm reading development in the child’s home language. The available evidence points firmly in the opposite direction.
Research on bilingual development shows that reading strategies transfer between languages: from a first language into a second, but also from a second language back into the first. Immersion students who begin as speakers of one language go on to develop reading comprehension levels in the second language comparable to native speakers, and that process strengthens reading comprehension in their home language in parallel.
This happens because reading in two languages forces the brain to do something monolingual reading does not require: comparing structures, inferring meaning from context, and consciously recognising grammatical patterns. That metalinguistic awareness — understanding how language works, not just using it — is exactly what separates a good reader from an excellent one, in any language.
In practice, this means a child at ISCB who reads complex English texts fluently is not “spending” their reading capacity on a foreign language. They are training a skill that they will later apply, naturally, to texts they read in their home language.
Confidence and motivation: the least visible, most decisive effect
Ask any teacher what best predicts a child’s long-term academic success, and many will not say “intelligence” — they will say “the confidence to try”. This is where English immersion has an effect that rarely makes headlines, but that we see every day in the classroom.
Research on academic self-efficacy — a student’s confidence in their own ability to reach learning goals — shows that this factor predicts effort, persistence, and the willingness to take on more demanding tasks. In studies on bilingual programmes, seven in ten students describe positive experiences and express confidence in their ability to communicate effectively in both languages, viewing bilingualism as a personal and academic asset rather than a burden.
When a child grows used, from an early age, to solving problems and expressing ideas in a second language, they internalise something valuable: that not knowing everything from the start is not an obstacle — it is the normal starting point for learning. That mindset carries over into maths, science, sport and any new challenge.
At ISCB, we prioritise an environment where making mistakes is a natural part of the process. This philosophy is also reflected in our ongoing work around emotional wellbeing at school, because we know academic confidence and emotional security go hand in hand.
What parents can expect to see, stage by stage
One of the most frequent questions from families joining an immersion model is simply: what will I see, and when? Although every child has their own pace, certain progress patterns repeat with notable consistency.
In Early Years (ages 3 to 5), the first months show listening comprehension advancing much faster than speech: the child understands instructions, songs and stories in English before producing full sentences. By the end of this stage, most children take part confidently in routines and play entirely in English, without translation support.
In Primary, the leap is most visible in literacy: pupils begin reading progressively more complex texts and writing with their own structure, rather than simply copying patterns. This is also the stage where families often notice their child “thinking” in English in certain contexts — playing, solving maths problems — without needing to translate mentally.
In Secondary, with preparation for qualifications such as the Cambridge IGCSE, performance is measured in terms of written argumentation, critical analysis and the ability to defend a thesis in academic English. Pupils who have lived through immersion from an early age arrive at this stage with a foundation that turns these demands into a natural progression rather than a sudden hurdle.
An approach that goes beyond language
The academic performance that immersion produces does not happen in isolation. It rests on a coherent pedagogical model, specialist teaching staff, and an environment that stimulates curiosity beyond the classroom. Learning in an international setting multiplies the opportunities to practise the language in real contexts, alongside classmates from dozens of different nationalities.
At ISCB, we shape our pupils’ education with the long term in mind: every gain in reading comprehension, every step forward in mathematical reasoning, and every extra ounce of confidence are pieces of the same project. That is why, by the time we come to preparing our students for university, the groundwork has already been years in the making.
We believe in holistic development, where fluency in English is a tool in service of the child’s growth, not an end in itself. This vision is part of our commitment to educational excellence, aimed at shaping young people with genuine autonomy and curiosity for learning.
English immersion does not just teach a language: it trains the mind to reason better, read better, and face challenges with greater confidence in every subject. This is what we see every day at International School Costa Brava.
Would you like to see this model in action with our pupils? Check our upcoming information sessions and discover the progress your child could make.
