Bilingualism, Language Acquisition, and CLIL in Education

Posted on Jun 29, 2025 in Early Childhood Education Teacher (Teaching Degree)

Module 1: Bilingualism, Benefits, and Second Language Acquisition

1. Understanding Bilingualism

In the 1950s, it was commonly believed that learning a second language (L2) negatively affected one’s first language (L1) proficiency. However, this view evolved significantly.

In the 1980s, Jim Cummins’ Developmental Interdependence Hypothesis emerged, stating that second language acquisition depends on the development of one’s first language. If students have strong skills in their first language, they can transfer those skills to the second language, making learning easier.

His Common Underlying Proficiency (CUP) Theory explains that languages are not completely separate in the brain. Instead, they share a common base of knowledge and skills. For example, if a student knows how to organize ideas or read well in their first language, they can use those same skills when learning another language.

To explain this, Cummins uses the dual iceberg metaphor. On the surface, different languages look separate, like two icebergs. But under the water, they are connected, sharing the same foundation. This means that improving the first language also helps develop the second language.

In education, this theory supports bilingual programs that strengthen the first language before introducing academic content in the second language. In methods like CLIL or EFL, a strong first language foundation makes it easier to understand and learn in a second language.

2. Benefits of Bilingualism

2.1. Why Bilingualism Matters

The benefits of bilingualism are numerous, grouped into linguistic and cognitive advantages.

The most obvious benefit is the ability to function in more than one language. A bilingual person can communicate with more people and in more places than a monolingual individual. Knowing a second language provides the opportunity to study or work in other countries where that language is spoken. It also opens doors to other cultures, which, as a result, can foster a more open and tolerant mindset and an understanding of different ways of acting and viewing the world.

A classic model of bilingualism supports the idea that the knowledge and skills acquired in one language transfer to the other language; in other words, both languages “operate” through a common system. This implies that a child will develop a similar level in both languages, as both stem from the same “central operator.”

Additionally, being bilingual enhances metalinguistic awareness, the ability to think about language itself. Since the 1960s, many studies have investigated bilingual individuals’ awareness of grammar, words, and sounds. Among other findings, research has shown that bilinguals tend to be more comfortable with synonymy and ambiguity, as they recognize that the relationship between a word and its meaning (or meanings) is arbitrary. Some experts discovered that bilingual children were better at detecting whether a sentence was grammatically correct, even if its meaning was nonsensical.

While favorable linguistic consequences associated with bilingualism seem obvious, many researchers have also focused on uncovering cognitive benefits. The groundbreaking study by Peal and Lambert in 1962 was the first to find advantages in bilingualism. This research involved ten-year-old Canadian children who were bilingual in English and French. The study found that their cognitive ability was superior to that of their monolingual peers when performing both verbal and non-verbal intelligence tests. The researchers proposed several explanations, including that bilingual children found concept formation easier and had greater mental flexibility. Since then, hundreds of studies have confirmed the linguistic and cognitive benefits of bilingualism.

One of the most notable advantages is the improvement of executive control. Essentially, executive control refers to a set of skills: the ability to focus on certain things while ignoring others; the ability to resist or inhibit a habitual reaction when beneficial; the ability to store and manipulate short-term information; the ability to think about multiple concepts simultaneously; and the ability to plan and solve problems. Bilingual individuals, both children and adults, tend to perform better on tasks designed to assess executive control.

Studies have also shown that bilingualism promotes divergent thinking. This type of thinking refers to the ability to view a problem and generate multiple possible responses or solutions rather than just one “correct” answer. A person with this ability would come up with more original or creative solutions to a problem. It appears that having two or more words for many objects or concepts, thanks to knowing two languages, fosters divergent thinking.

Some researchers have discovered that the benefits of bilingualism extend far beyond childhood. Bialystok, Craik, and Freedman (2007) found that the onset of dementia was delayed by an average of four years in bilingual individuals compared to monolinguals. It is believed that this is due to the greater cognitive demands required when using two or more languages regularly.

It is important to remember that the definition of “bilingual” does not necessarily mean that a person has exactly the same level of proficiency in both languages. Bilingualism exists on a spectrum, and there are many more bilinguals in the world than monolinguals. In fact, those who master two languages equally are a minority, but many people have communicative competence in two or more languages. It is not necessary to know a second language perfectly to experience the cognitive benefits of bilingualism—although the greater the proficiency in the second language, the greater the benefits.

2.2. Is Early Immersion in a Second Language Beneficial?

Young children are capable of learning a second language with much greater ease, speed, and efficiency than at later ages, as their neuronal and synaptic plasticity is significantly higher, with numerous connections between neurons forming during these early years. Some experts refer to children under the age of seven as “linguistic geniuses.” This increased ability to acquire a second language can manifest at any of the different levels of language:

• Phonological: Perception and reproduction of the sounds of a language.
• Morphosyntactic: Word formation and sentence structure according to grammatical rules.
• Lexical: Vocabulary richness.
• Semantic: Comprehension and production of organized and fluent discourse.

On the other hand, there is a clear decline in the ability to learn a second language after the age of seven or eight. Therefore, if exposure to the second language occurs later, phonetic perception and production, vocabulary, and grammatical structures will not be acquired with the same ease and naturalness. This is because the “sensitive period”—those early years of a child’s life—will have passed, and the learning process will need to be more formal. Instead of acquiring the language naturally, the child will have to explicitly learn it. For this reason, specialists widely accept the idea that exposure to two languages from early childhood is the ideal way to achieve bilingualism.

For example, during the first months of life, babies can distinguish multiple sounds (phonemes) from different languages. After a few months, however, this “range” begins to narrow as the child’s brain specializes in the sounds of their native language, retaining only those they have frequently heard and discarding those that are not useful. This is why exposing a child to a second language as early as possible is advantageous—to prevent this “range” from closing and, instead, allow the second language to become part of their repertoire of known and perceived sounds.

Similarly, the accent of a child who acquires a second language at an early age will be very similar to that of a native speaker of that language. In contrast, a child who learns the language later will always retain traces of their native accent.

2.3. Myths and Realities: Can Bilingualism Hinder a Child’s L1 Development?

There are some beliefs that bilingualism could negatively affect a child’s language development, causing difficulties in acquiring their mother tongue. In reality, negative attitudes toward early bilingualism are based more on misinterpretations and myths than on scientific findings.

The main myth is the idea that early bilingualism delays a child’s linguistic development. In reality, the pace of first-language development is similar in both monolingual and bilingual children. However, a bilingual child is acquiring two linguistic systems simultaneously, each with its own set of sounds, vocabulary, and syntactic structures. This process involves more neural and brain activity, which may give the impression that the bilingual child is developing more slowly. However, any slight initial discrepancies will gradually balance out.

Some examples can illustrate this point:

• The first words are typically spoken at approximately the same age by both monolingual and bilingual children. Bilingual children may take a few months longer to recognize or distinguish certain homophonous words (words that sound very similar), but these differences soon balance out in their linguistic development.
• Similarly, the vocabulary level in a bilingual child’s first language at the age of two or three may be (very slightly) lower than that of a monolingual child. However, when considering that the bilingual child possesses vocabulary in both languages, their total repertoire is equivalent to that of a monolingual child. In any case, differences within the first language will gradually balance out, and eventually, the bilingual child’s proficiency in their mother tongue will be equal to or even superior to that of a monolingual child. Initially, they tend to retain words in the language in which they first learned them, but they later acquire the equivalent term in the other language without any difficulty.
• Regarding grammar, a bilingual child must learn and respect the syntax of each language. They may occasionally mix grammatical structures from one language into the other, but with continuous exposure to both languages, these minor errors will naturally correct themselves, allowing the child to develop appropriate grammatical competence in both.

In conclusion, the potential challenges arising from the early acquisition of a second language are minimal, temporary, and easily overcome. Early immersion in a second language offers a wide range of advantages and benefits for a child’s linguistic development.

3. Second Language Acquisition Theories

3.1. Critical Period Hypothesis

(Content for this section is implied but not provided in the original text. It typically refers to a limited time frame in which language acquisition can occur easily and naturally.)

3.2. Krashen’s Hypotheses

Stephen Krashen’s theory of second language acquisition is highly influential, comprising five main hypotheses:

1. The Acquisition-Learning Distinction: This is the most fundamental hypothesis. Krashen distinguishes between two independent systems of second language performance: the ‘acquired system’ and the ‘learned system’.

   • The ‘acquired system’ or ‘acquisition’ is the product of a subconscious process very similar to how children acquire their first language. It requires meaningful interaction in the target language—natural communication—where speakers focus on what they are communicating, not how they say things.
   • The ‘learned system’ or ‘learning’ is the product of formal teaching and is a conscious process that results in conscious knowledge about the language, such as grammar rules. According to Krashen, ‘learning’ is less important than ‘acquisition’.

2. The Monitor Hypothesis: This explains the relationship between acquisition and learning, defining the influence of the second on the first. The monitoring function is the practical result of learned grammar. According to Krashen, the acquisition system gets you to start communicating, while the learning system is like the ‘monitor’ or the ‘editor’. The ‘monitor’ acts in a planning, editing, and correcting function when three specific conditions are met:

   1. The second language learner has sufficient time to think.
   2. They think/worry about correctness.
   3. They know the rule.

   According to Krashen, the role of the monitor is—or should be—minor, used only to correct deviations from ‘normal’ speech and to give speech a more ‘polished’ appearance.

   Krashen suggests there is variation among language learners. He distinguishes:

   1. Learners who use the ‘monitor’ all the time (over-users).
   2. Those learners who have not learned or who prefer not to use their conscious knowledge (under-users).
   3. Those learners who use the ‘monitor’ appropriately (optimal users).

   A person’s psychological profile can be interesting. Often, extroverts are under-users, while introverts and perfectionists are over-users. Lack of self-confidence is also frequently related to the over-use of the ‘monitor’.

3. The Natural Order Hypothesis: This is based on research suggesting that the acquisition of grammatical structures follows a ‘natural order’ which is predictable. For any language, some grammatical structures tend to be acquired early while others late. This order seemed to be independent of the learner’s age, first language, and conditions of exposure. Although results were not always 100% consistent in studies, there were statistically significant similarities that reinforced the existence of a Natural Order of language acquisition. Krashen, however, argues that the implication of the natural order hypothesis is not that a language curriculum should be based on the order found in the studies. In fact, he rejects grammatical sequencing when the goal is language acquisition.

4. The Input Hypothesis: This is Krashen’s attempt to explain how the learner acquires a second language. The Input Hypothesis is only concerned with ‘acquisition’, not ‘learning’. According to this hypothesis, the learner improves and progresses along the ‘natural order’ when they receive second language ‘input’ that is one step beyond their current stage of linguistic competence. For example, if a learner is at a stage ‘i’, then acquisition takes place when they are exposed to ‘Comprehensible Input’ that belongs to level ‘i + 1’. Since not all learners can be at the same level of linguistic competence at the same time, Krashen suggests that natural communicative input is key to designing a syllabus, ensuring that each learner will receive some ‘i + 1’ input that is appropriate for their current stage of linguistic competence.

5. The Affective Filter Hypothesis: This is Krashen’s view that several ‘affective variables’ play a role in second language acquisition. These variables include motivation, self-confidence, and anxiety. He claims that learners with high motivation, self-confidence, a good self-image, and a low level of anxiety have a better chance of success in second language acquisition. The opposite can ‘raise’ the affective filter and form a ‘mental block’ that prevents comprehensible input from being used for acquisition. When the filter is ‘up’, it impedes language acquisition. On the other hand, positive affect is necessary, but not sufficient on its own, for acquisition to take place.

3.3. Key Language Acquisition Elements by Jim Cummins

Professor Jim Cummins is one of the world’s leading authorities on bilingual education and second language acquisition. Four of his most influential contributions are:

1. Different types of language: BICS/CALP
2. Common Underlying Proficiency (CUP)
3. A way to assess task difficulty
4. Additive/Subtractive Bilingualism

Mainstream teachers who have knowledge of Cummins’ insights will be in a much stronger position to help ESL students in their classes learn mainstream subjects while at the same time developing their English language proficiency.

1. BICS/CALP Distinction

Cummins makes the distinction between two kinds of language proficiency:

1. BICS (Basic Interpersonal Communication Skills): These are the “fundamental” skills of listening and speaking and are typically acquired quickly by students.
2. CALP (Cognitive Academic Language Proficiency): This is the basis for the student’s ability to meet the academic demands of any subject.

Cummins says that some children achieve native speaker fluency (i.e., BICS) within two years of immersion in the target language, but it takes between 5-7 years for a child to work like a native speaker in an academic language (CALP). In other words, a non-native speaker needs to develop CALP.

Implications for Teachers:

• Non-native students who have a high degree of fluency in everyday spoken English (BICS) do not always have the same academic language proficiency (CALP).
• Students can have difficulty with the demands of comprehending and composing academic texts. In particular, it is very possible they will have significant gaps in academic skills and vocabulary.

2. Common Underlying Proficiency (CUP)

When learning one language, a child acquires skills and implicit metalinguistic knowledge that they can use when working in another language. This is the Common Underlying Proficiency (CUP), illustrated by the Iceberg Metaphor.

CUP serves as the foundation for the development of both L1 and L2. Logically, improving CUP in one language will have a beneficial effect on the other language(s). This theory also explains why L2 can help with L1 and vice versa.

Implications for Teachers:

• It is very important to encourage students to continue their native language (L1) development. When parents ask about the best ways they can help their child at home, you can suggest that the child should have the opportunity to read extensively in their own language.
• You can suggest that parents make some time every day to discuss, in their native language, what they did in school. For example, to talk about a science experiment, or ask about history, or ask the child to explain how they solved a mathematics problem.

“Conceptual knowledge developed in one language helps to make input in the other language comprehensible.” (Cummins, 2000)

If a child understands the concept of honesty in their L1, then all they need is to acquire the label for the same terms in English. This is more difficult, however, if they have to acquire both the label and the concept in their second language.

It is very important that students be encouraged to continue their native language development. When parents ask about the best ways they can help their child at home, you can reply that the child should have the opportunity to read extensively in their own language.

3. Evaluating Task Difficulty

Cummins created a model to evaluate the difficulty of tasks for our students based on two things: cognitive demand of the task and the context of the task.

The context of a task can be:

• Context-embedded: A task in which the student has access to visual and oral help. For example, they can look at illustrations of what is being talked about or ask questions to confirm understanding.
• Context-reduced: A task such as listening to a lecture or reading dense text, where there are no sources of help other than the language itself.

Four quadrants result from crossing these two elements (cognitive demand and context):

(Image of Cummins’ Quadrant model would typically be inserted here, showing the four quadrants: A, B, C, D)

The D quadrant task (cognitively demanding and context-reduced) is likely to be the most difficult for students. This is especially true for non-native speakers in their first years of learning English (i.e., before they have developed CALP). However, it is essential that students develop the ability to do these tasks, because academic success depends on it.

Look inside a quadrant above to see examples of that type.

For more on assessing task difficulty, using Bloom’s Taxonomy, click the button below.

(Button for “Task difficulty” would typically be here)

Implications for Teachers:

• If teachers have an awareness of the likely difficulty of a task, based on Cummins’ model, they can judge its appropriateness for the non-native speakers in their classes and in this way avoid much frustration.
• This does not mean, however, that ESL students should be fed a diet of cognitively-undemanding tasks. It may be beneficial to use such activities in the student’s early days at school, in order to build confidence, or as a lead-in to a more challenging activity.
• However, teachers should switch soon to tasks that engage the students’ thinking processes, and make these tasks accessible by providing visual or other support. Once students are comfortable with such activities, they can be gradually exposed to tasks that are both cognitively-demanding and context-reduced.

For an interesting discussion of what happens when teachers start with a D quadrant task and then have to modify it to avoid embarrassment and confusion in the classroom, see the Mackay article listed in the references below.

Coelho, see reference below, has a useful example of how to use the quadrant in designing support for ESL students doing a science project.

4. Additive/Subtractive Bilingualism

Cummins draws the distinction between two types of bilingualism:

• Additive bilingualism: A form of bilingualism in which the first language continues to be developed and the first culture to be valued while the second language is added.
• Subtractive bilingualism: A form of bilingualism in which the second language is added at the expense of the first language and culture, which diminish as a consequence.

Cummins (1994) cites research which suggests students working in an additive bilingual environment succeed to a greater extent than those whose first language and culture are not valued by their schools and by the wider society.

Implications for Teachers:

• The dangers of subtractive bilingualism for non-native English speakers in international schools are obviously not as strong as, say, for the children of immigrants to the USA.
• Nevertheless, we should do all we can to demonstrate to non-native English students that their cultures and languages are equally as valid and valued as the Anglo-American culture and English language that inevitably dominates English-medium international school life.
• Teachers and departments should explore ways to incorporate the different cultural backgrounds of our students into their daily teaching and curricula.

Mainstream teachers who have knowledge of Cummins’ insights will be in a much stronger position to help ESL students in their classes learn mainstream subjects while at the same time developing their English language proficiency.

Module 2: CLIL Components: Analyzing CLIL in Practice

1. What Does CLIL Stand For?

CLIL stands for Content and Language Integrated Learning. Culture is fundamental because languages are our identities, and CLIL is an approach that develops good teaching practice in a bilingual context. Models of bilingual education include:

• Dual Language Immersion: E.g., a class might split its day between English and Spanish instruction.
• Transitional Bilingual Education: Often used to ease non-native speakers into a new language.
• Content and Language Integrated Learning (CLIL): One subject taught in only one language.

The Four Cs of CLIL are:

• Content: Activities focusing on subject-specific knowledge and skills.
• Communication: Activities promoting language use in context.
• Cognition: Activities developing thinking skills.
• Culture: Activities fostering cultural awareness and understanding.

2. Do Coyle’s Principles of CLIL

Education is about the quality of learning. Principles include:

• Clarity in concepts and skills.
• Deep learning, encompassing:
  • Automatization (acquisition)
  • Integration
  • Internalization of learning

Demands of CLIL include:

• Time
• Practice
• Effort
• Collaboration
• Languaging: Asking students about what they think they’ve learned, talking about what you’ve learned.

We have to analyze the language. The Triptych of language analysis in CLIL includes:

• Language of Learning: Key terms (content), content-obligatory, predictable, subject-specific, should be prepared, and language of concepts.
• Language for Learning: Vocabulary needed for meaning-making, functional, content-compatible, predictable, transferable, should be prepared, and language of tasks/activities.
• Language Through Learning: The emergent language that students produce as they engage with content and tasks.

3. Phil Ball’s CLIL Methodology

Phil Ball states, “Every subject is a language subject.” Teachers in CLIL need to adjust their methodology:

• Reduce teacher-talk = increase student-talk.
• Increase student-talk = adjust material.

How do we plan for this? Stephen Covey’s advice: “Begin with the end in mind” (the objectives).

Wiggins and McTighe’s “Backward Design” is a key planning framework:

1. Identify Desired Results (Knowledge and Competencies): What final product is desired? What knowledge and skills are necessary for this final product? What essential understanding would you like them to take away? This includes Concepts (Content – what), Procedures (Skills – how), and Language (language of and language for learning to work on concepts and procedures).

   Formula for Learning Objectives:

   • We Are Learning To (WALT): For example: “to identify types of butterflies by defining and describing their characteristics in small groups using adjectives of size, shape, color, and pattern.”

   Different types of abilities:

   • Cognitive
   • Intrapersonal/Affective
   • Interpersonal/Behavioral

   Bloom’s Taxonomy is a classification system for learning objectives, aiding in the design of learning intentions/objectives and focusing on cognitive and knowledge dimensions of learning.

   • Students Will Be Able To (SWBAT)

2. Determine Acceptable Evidence (Assessment): What – assessment criteria (WILF), How/Who – instruments, and When – formative vs. summative.

   • What: Good success criteria are formulated as observable behaviors (as opposed to abilities), are expressed in the third person singular of the present tense, and answer “What I’m Looking For?” (WILF).
   • How: Rubric
   • When: Formative (process) or Summative (exam)

3. Plan Learning Experiences (Sequence Activities for Learning): Action plan, types of activities, and materials and resources.

   Suggested lesson sequence: starting a lesson (arouse curiosity, activate prior knowledge), presenting new language, controlled practice, freer practice, and finishing a lesson.

Backward Planning Summary:

1. Think about a final (challenging) product (objectives: SWBAT/WALT). Abilities + concepts.
2. Assessment (WILF, When, and How).
3. Sequence of Activities.

4. According to Cummins’ Quadrant, What is “Cognitive Demand vs. Contextual Embeddedness” and How is it Related to CLIL?

It’s a model to evaluate the difficulty of tasks for students based on two factors: cognitive demand and contextual embeddedness. A context-embedded task provides students with visual and oral support. A context-reduced task, such as listening to a lecture or reading dense text, offers no support beyond the language itself.

This relates to CLIL because the goal is to balance cognitive challenge with sufficient language support, helping students advance both their content knowledge and linguistic skills.

5. What are HOTs and LOTs According to Bloom’s Taxonomy?

HOTs (Higher-Order Thinking Skills) include analyzing, evaluating, and creating. LOTs (Lower-Order Thinking Skills) include remembering, understanding, and applying. These categories represent different levels of cognitive processes.

6. What is Scaffolding and Why is it Important for CLIL?

It’s an educational technique where the teacher provides temporary support to students to help them achieve a higher level of understanding or skill. Scaffolding is crucial in CLIL to make cognitively demanding content accessible to students who are simultaneously learning the language of instruction.

7. What Types of Activities are Used in CLIL?

Common CLIL activities include:

• Project-based learning: Applying content knowledge and language skills.
• Collaborative activities: Students work together to solve problems.
• Discussions and debates: Discussing topics to practice argumentation.
• Role-playing.
• Interactive experiments.
• Reading and writing tasks.
• Multimedia projects.