Bridging Languages and Learning: A Short Guide to BICS, CALP, CUP & CALS for Multilinguals

Posted on 07/04/202508/10/2025

Many multilingual children experience a paradox: some may chat fluently in a new language but struggle academically, whilst others may grasp complex academic concepts yet find casual conversations about everyday topics difficult.

This is where four essential concepts – BICS (Basic Interpersonal Communicative Skills), CALP (Cognitive Academic Language Proficiency), CUP (Common Underlying Proficiency), and CALS (Core Academic Language Skills) – help us understand multilingual development and learning success.

1 – Understanding BICS, CALP and CUP

Jim Cummins (1979, 2000) introduced the distinction between BICS and CALP to explain why multilingual children may appear fluent in a language yet struggle in school.

BICS: Basic Interpersonal Communicative Skills

BICS refers to everyday social language used in informal interactions – this is the language used on the playground, when greeting people, or the language used in casual conversations.
This type of language develops relatively quickly (within 6 months to 2 years) once a child is exposed to a new language.
However, conversational fluency can be misleading – just because a child speaks effortlessly in daily situations does not mean they have the language skills required for academic success. This is where the language development of children who were exposed to the target language since day one and those who start learning it at school converge: they are all language learners!
However, multilingual children exposed to the new language only in formal settings, and learn the academic language (CALP) first, may struggle with BICS in that language and find it difficult to engage in informal conversations about everyday topics.

CALP: Cognitive Academic Language Proficiency

CALP is the ability to understand, process, and use language in academic settings – when reading textbooks, writing essays, and solving math problems.
Developing CALP takes significantly longer than BICS – typically 5 to 7 years, and in some cases even longer, depending on the way the academic language is transmitted and fostered over the years.
Academic skills within CALP include critical thinking, reasoning, analyzing texts, summarizing, inferring, comparing and contrasting, and writing structured arguments.
Multilingual children who lack CALP often struggle with schoolwork. They might appear fluent when reading (decoding), but might not fully grasp the meaning of what they are learning.

This distinction explains why some multilingual children can engage in friendly chatter but struggle with schoolwork, and why others excel academically but find informal social interactions challenging.

Most studies about multilingual learners focus on successive multilinguals, i.e. children who learn the additional language usually in formal settings and after having achieved a great level of proficiency in their first language. Children who have been exposed to multiple languages early on, i.e. simultaneous multilinguals, often have different approaches to learning additional languages, as we explain in our post about Compound, Coordinate and Subordinate Multilinguals.

CUP: The Bridge Between Languages

The Common Underlying Proficiency (CUP) model (Cummins, 1981) explains how knowledge and skills transfer across languages.

Language learning is not isolated – once a child develops academic language in one language (in the picture here below: language orange for example), they can apply these skills in another (here below: language blue).
This means that strong literacy and academic skills in the home/heritage language will support learning in the school language, and vice versa.
Concepts such as problem-solving, reading comprehension, and logical reasoning exist independently of language and can be transferred across languages. Multilinguals who learn these skills in the language of instruction, need opportunities to make this transfer to the home/ heritage language(s) – ideally at school and at home.

For parents and educators, CUP highlights the importance of supporting the home/heritage language, as it strengthens overall academic success in multilingual children.

The dual Iceberg metaphor illustrates Cummins’ Developmental Interdependence Hypothesis which addresses the functional interdependence between the development of language orange and language blue skills. The tips of the iceberg above the surface of the water represent the BICS in the two separate languages, that can appear to be qualitatively distinct.

Languages often appear to have fundamentally different features when looking at them from the surface. The part of the iceberg underneath the surface of the water representing CALP (and CALS; see here below), represents Cummins’ idea that learning the two (or more) languages involves the same basic processes and skills and that learning one makes it easier to learn another (or others), thanks to the CUP .

2 – Expanding CALP for Academic Success with CALS

Core Academic Language Skills (CALS), also developed by Cummins, extends the concept of CALP. CALS focuses on the specific language skills needed for academic success in different subjects.

CALS reflect the discourse patterns and challenges of language and literacy use within he social context of schooling to a greater exent than other registers of language development (Cummins, 2021 and Barr et al., 2019).

Academic language is not uniform – the language of math is different from the language of science, history or geography.
CALS includes subject-specific vocabulary, complex sentence structures, and different ways of reasoning and presenting arguments.
Students need explicit instruction in CALS to effectively navigate different academic registers and genres.

Ideally, multilingual students would learn subjects in both or several of their languages, following CLIL (Content and Language Integrated Learning), from early on.

3 – Supporting BICS, CALP, and CALS in Successive Multilinguals

As mentioned before, studies about multilingual learners focus on successive multilinguals – i.e. children who learn the additional language after the first language(s) have been consolidated, usually in formal settings, emphasising that their strongest language plays a crucial role in developing academic success. However, they may not have had the opportunity to develop BICS in the school language before they are expected to perform academically and build their CALP.

How to Support BICS in Successive Multilinguals

Create social opportunities: Playdates, extracurricular activities, and peer interactions help children develop social fluency in the new language.
Encourage role-playing: Practicing common phrases, small talk, and real-life scenarios boosts confidence in informal interactions.
Use visual and contextual support: Gestures, facial expressions, and visual cues help children grasp social language in context.
Promote bilingual peer support: Having a buddy who speaks both the home/heritage language and school language eases communication and builds confidence.

It is important to notice that once successive multilinguals have achieved a certain level of fluency, they might not benefit from continuous translating to their home/heritage language, but prefer to fully immerse into the target language.

**How to Support CALP and CALS in Successive Multilinguals**

The following should be practiced at school and at home:

Encourage reading across genres: Exposing children to fiction, nonfiction, and subject-specific texts strengthens academic vocabulary.
Discuss school topics in multiple languages: Talking about science, math, and history in the home/heritage language supports concept development and knowledge transfer.
Develop metalinguistic awareness: Helping children recognize connections between languages enhances language learning and academic success.
Provide structured academic language practice: Encourage debates, structured discussions, and presentations in different languages to build confidence in academic registers.
Use scaffolding techniques: Graphic organizers, sentence starters, and guided questioning support academic language development.

How to support BICS, CALP and CALS in Simultaneous Multilinguals

It is crucial to recognize that simultaneous multilingual learners do not learn additional languages in the same way as successive multilinguals. Simultaneous multilinguals develop their languages alongside each other from early on, often without a clear dominance. When one of their early learned languages is the language of instruction, their learning will barely differ – if at all! – from the one of monolingual learners. If the language of instruction is an additional language to those they aquired from early on, their learning is likely to procede first through the mediation of the first languages (as subordinate multilinguals) and they might need some support during the early stages of language learning. However, they will very likely be reaching higher levels of proficiency faster than successive multilinguals, and they will rather learn the additional language in a coordinate way, i.e. preferring to keep their languages separated for example by topic, subject area, setting, person etc..

Their BICS may emerge naturally in all regularly used languages through play and social interaction in everyday situations, whereas CALP and CALS will require more intentional scaffolding across all contexts. Thanks to CUP, cognitive and conceptual knowledge will be transferred between their languages, and rich conceptual discussions will be nurtured in any language that the children are required to share their knowledge in. In the same way, their academic language will be strengthened across all those languages (Cummins, 2008).

Simultaneous multilingual learners benefit from the exposure to a wide range of vocabulary, genres, and registers in each language they are expected to use academically. However, for this to happen across all their languages, simultaneous multilinguals who learn an additional language at school will need exposure to the language of instruction also outside of the classroom setting.

Maintaining regular use of each language in cognitively demanding contexts – discussing books, explaining reasoning, making predictions etc. – helps deepen CALP and CALS simultaneously. Parents, teachers and other professionals should though not expect any “balanced” proficiency in all the languages. The opposite, with one or two languages being more dominant than others, is more realistic.

In our videos on Activities for Multilingual Families and The Toolbox for Multilingual Families we share ideas on how to support multilingual children’s language skills in a motivating and effective way. Crucially, support should be consistent, contextualised, and responsive to each child’s evolving language constellation (Limacher-Riebold, 2022).

Conclusion

Understanding the differences between BICS, CALP, CUP, and CALS is essential for supporting all multilingual learners. It is necessary though to tailor the support to the different kinds of multilingual learners. While conversational fluency may come quickly to some, academic proficiency takes years to develop and requires intentional support in both or all languages. Encouraging the use of the home/heritage language alongside the school language strengthens overall academic success.

– The content of this post is part of my trainings, workshops and webinars for parents, teachers and other professionals at Ute’s International Lounge.

References

Barr, C.D., Uccelli, P. and Phillips Galloway, E. (2019) Specifying the academic language skills that support text understanding in the middle grades: The design and validation of the core academic language skills construct and instrument. Language Learning 69, 978-1021.
Cummins, J. (1979). Cognitive/Academic Language Proficiency, Linguistic Interdependence, the Optimum Age Question, and Some Other Matters. Working Papers on Bilingualism, (19), 121-129.
Cummins, J. (1981). Age on arrival and immigrant second language learning in Canada: A reassessment. Applied Linguistics, 2(2), 132-149.
Cummins, J. (2000). Language, Power and Pedagogy: Bilingual Children in the Crossfire. Multilingual Matters.
Cummins, J. (2008). Teaching for Transfer: Challenging the Two Solitudes Assumption in Bilingual Education. In J. Cummins & N. Hornberger (Eds.), Encyclopedia of Language and Education (Vol. 5). Springer.
Cummins, J. (2021). Rethinking the Education of Multilingual Learners, Multilingual Matters, p.183.
Limacher-Riebold, U. (2024, April 5). How to help multilingual children with homework. Multilingual-Families.com (https://multilingual-families.com/how-to-help-multilingual-children-with-homework/)
Snow, C. E., & Uccelli, P. (2009). The challenge of academic language. In Olson, D. & Torrance, N. (Eds.), The Cambridge Handbook of Literacy, 112-133.

I invite you to watch my video about balancing multiple languages at home.

Some thoughts about fluency in language

Posted on 16/05/201522/12/2024

What does it mean to be “fluent” in a language?

What is fluency? There are many different definitions of fluency, so for example it can be “the property of a person or of a system that delivers information quickly and with expertise”, or “the smoothness or flow with which sounds, syllables, words and phrases are joined together when speaking quickly” (Bruce Harrell, 2007).

Usually we consider someone fluent in a language when he/she has a high level of language proficiency. But what would be a high level, and what makes you say that someone is proficient in a language?

When it comes to defining the level of fluency of someone in a foreign language or a learned language, fluency seems to determine the spontaneous, “flowing” language use, as opposed to slow, halting use.

But is fluency necessary or even sufficient to determine – or even define – one’s language proficiency?

A person can be a fluent language user (i.e. use the language in a quick, not-halting way) but with a narrow vocabulary, limited discourse strategies and an inaccurate word use. One may even be illiterate but a fluent speaker. In fact, native language speakers are often incorrectly referred to as fluent.

When one considers the term of fluency in correlation of multilinguals, fluency is the ability to be understood by both native and non-native listeners. And when one becomes native or nearly native in the other language – whatever native or nearly native means! – , he/she can be considered multilingual; no matter if the two or more languages were learnt simultaneously or subsequently (i.e. one after the other).

This definition of “bilingual” or “multilingual” is dated. Since the 80ies a bilingual is not defined by his/her level of fluency! In fact, to be bilingual – or multilingual for that matter! –, one should be able to use two (or more!) languages on a regular basis. This implies that one is able to speak both languages to an extent to be understood and to make himself/herself clear in conversations.

A person would be an emergent bilingual or multilingual, if he/she is learning an additional language, starts understanding it and speaking it on a beginners’ level.

In terms of proficiency, fluency encompasses some skills that can be related but also taken separately: comprehension, speaking, reading (reading comprehension), writing. These skills can be acquired simultaneously or separately.

That after age 11 it is “impossible” to acquire a language (i.e. in the more natural way, using memory based processes), is a myth!

Everyone can acquire another language also later in life, it just requires more effort to attain the same results, especially on a phonetic level. (more about this in another post)

BICS is the language that is necessary for day to day living, indulging conversations with friends and informal interactions. CALP is the language we need to understand and discuss content in the classroom. If we compare BICS and CALP: BICS is rather context embedded, which means that the conversation is often face-to-face, and offers many cues to the listener such as facial expressions, gestures and concrete objects of reference. CALP, on the other hand, is rather context-reduced. It is the language of the classroom in which there are fewer non-verbal cues and the language is more abstract.

On a cognitive level, the BICS is undemanding. It is easy to understand, deals with everyday language and occurrences and uses simple language structures. CALP is a more demanding language and relates to abstract concepts, has a specialized vocabulary and uses a more complex language structure.
If we look at Jim Cummin’s quadrant about the BISC/CALP, along two scales and with some school activities and subjects added in the quadrants of the chart:

The BISC/CALP can be used to describe the language proficiency of single language students, but it is primarily used as a way to understand and evaluate the language level of students learning an additional language; in Cummins’ studies: English as a second language. Cummins studies of second language learners indicates that children can develop BICS (social language) in 3 years, but it takes 5-7 years for a child to work on the same level as native speakers in CALP.

If we consider BICS and CALP on an iceberg model, where BICS is the part we see on the surface and CALP what lies underneath the surface (the biggest part to be achieved in language learning!), in a bilingual person – with L1 and L2 – there is a common area of language proficiency which provides the foundation for the use of both languages, the Common Underlying Proficiency (CUP).

Fact is that our L2 or any additional language we learn, grows from the foundation of the L1 or the languages we have acquired and learned before. Therefore, the stronger the first language(s), especially the CALP level of it or them (!), the stronger the additional language can be. Our language ability can easily be over-estimated by looking at the BISC and not realizing the complexity and difficulty that second or additional language students have in acquiring CALP in the other language.

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When talking about fluency or the linguistic competence of bilinguals or multilinguals it becomes even more complicated as “bilingual” is, in itself not a very clear-cut term.

In defining a bilingual, “the pronunciation, morphology and syntax used by the speaker in the language are key criteria used in the assessment”.

Also the mastery of the vocabulary is taken into consideration, but the lexicon can be easily learnt without knowing the proper use of it. – The proper use of vocabulary requiring a more in-depth study of the semantics.

Fact is, that testing or assessing the grammatical competence of a speaker is much easier than communicational competence.

Furthermore, we have to consider that we learn languages for different purposes and use them in different contexts, for what François Grosjean (1997, 2010) defines as the Complementary Principle, that “states that bilinguals usually acquire and use their languages for different purposes, in different domains of life, with different people. Different aspects of life often require different languages. Some languages will cover many domains of life, others less, and some will cover domains along with another language(s). Rare will be the bilinguals who will have all domains of life covered by all their languages.”

The Complementary Principle impacts:

– the fluency : “since if a language is spoken in a reduced number of domains and with a limited number of people, then it will not be developed as much as a language used in more domains and with more people” (Grosjean, 2015)

– language dominance: “many bilinguals are dominant in a language (…) as opposed to balanced. Dominance is difficult to define and is based not only on language fluency and language use, but also on how the languages are distributed across domains of life” (Grosjean, 2015)

– translation: “unless bilinguals have domains covered with two languages or have acquired the language they are translating into in a manner that puts the emphasis on translation equivalents, hence building a bridge between their languages, they may find themselves without the resources to produce a good translation” (Grosjean, 2015)

In order to have a clearer picture of ones communicational competence, multilinguals should be assessed through the use of appropriate utterances in different settings.
You can find countless articles and videos about “fluency” in languages…

Fluency, accuracy and complexity, in formal settings

Fluency can focus on the content and what the learner is communicating. It refers to how well learners communicate meaning in the target language. It is about with how much ease learners can speak and how well they can communicate without pauses or hesitations, without needing to search for words or phrases, without having to consider the language of what they are about to say. When learners are fluent, they might not necessarily be 100% accurate but they are generally comprehensible.
Examples of fluency activities are conversations, role plays, debates, and projects.

Accuracy refers to the form and focuses on how the learner is communicating. It is about how grammatically correct a learner uses the language system, if the use of tenses, verb forms, collocations, and colloquialisms are “correct” in the target language.

Important side-note: nobody (!) is 100% accurate all the time!

Accuracy activities focus on grammar exercises, gap fills, noticing activities etc. Usually this practice takes place in controlled and formal settings, like schools. Most of the time, these activities do not allow much variation and rather focus on “right” and “wrong”…
Teachers focus on correcting errors and that the highest level of accuracy is achieved.

Complexity refers to how the language production and performance is elaborate and varied.

Accuracy-oriented activities focus on the linguistic form and on the controlled production of grammatically correct linguistic structures in the L2 (Housen & Kuiken 2019). Fluency, Accuracy, and Complexity, are equally important for a skilled communicator.

What does “fluency” mean to you? What level of fluency do you think you have in your first, second, third… language? And how do you think you can improve your language skills?

In my language trainings I focus on the individual goals the client wants to achieve in the given language and together we choose the way and method that works better.

What I read so you don’t have to:

Cummins, Jim, ‘Cognitive/academic language proficiency, linguistic interdependence, the optimum age question and some other matters’, Working Papers on Bilingualism 19, 1979, 121–129.

Cummins, Jim, ‘Psychological assessment of immigrant children: Logic or intuition ?’, Journal of Multilingual and Multicultural Development 1, 1980, 97–111.

Cummins, Jim, The role of primary language development in promoting educational success for language minority students’, in California State Department of Education (ed.), Schooling and Language Minority Students: A Theoretical Framework, Evaluation, Dissemination and Assessment Center California State University, Los Angeles, 1981.

Cummins, Jim, Teaching for Cross-Language Transfer in Dual Language Education: Possibilities and Pitfalls, 2005.

Cummins, Jim, BICS and CALP: Empirical and Theoretical Status of the Distinction, in Brian V. Street and Stephen May, Literacties and Language Education, 2017, 59-71.

Grosjean, François, The bilingual individual. Interpreting: International Journal of Research and Practice in Interpreting, 2, 1997, 163–87.

Grosjean, François, Bilingual: Life and reality. Cambridge, MA: Harvard University Press, 2010.

Grosjean, François, Bicultural Bilinguals, International Journal of Bilingualism 2015, Vol. 19(5), 2015, 572–586.

Housen, Alex and Folkert Kuiken, Complexity, Accuracy, and Fluency in Second Language Acquisition, Applied Linguistics, vol.30, issue4, Dec. 2009, 461-473.

Noshik, Wartan, Complexity, Accuracy and Fluency in Second Language Acquisition: Speaking Style or Language Proficiency?, MA in UvL, 2019.

Michel, Marije, Complexity, Accuracy and Fluency (CAF), in Shawn Loewen & Masatoshi Sato, The Routledge Handbook of Instructed Second Language Acquisition, London, Routledge, 2017.

Benati, Alessandro, Focus on Form and Focus on Forms in Implicit Grammar Teaching Strategy, CUP, 2021.