Understanding Language Acquisition

 Objectives

By the end of this text, you’ll be able to:

• Reflect on the key features and stages involved when children acquire their first language (L1).
• Understand and analyze the similarities and differences between acquiring a language naturally (acquisition) and learning it consciously (learning).
• Compare how acquiring a first language (L1) differs from acquiring or learning a second language (L2).

1. What Is Competence in Language?

When we talk about competence in language, we mean the internal knowledge speakers have about their language—things like sounds (phonology), word forms (morphology), vocabulary (lexicon), and meaning (semantics). Noam Chomsky, a pioneering linguist, described this as “mental grammar” — the system your brain naturally builds, without formal teaching.

Think about walking: you don’t need lessons to learn to walk, right? You just do it. The same applies to language. Babies aren’t taught language like they’re taught math or history; they absorb it effortlessly (Chomsky, 1994). The truth is, language acquisition is an innate ability.

But there’s a difference between competence—what we know—and performance—how we actually use language in real life. For example, if someone says, “We loosed the car keys last weekend,” is this a mistake in their underlying knowledge of English (competence), or just a slip of the tongue (performance)?

• A native speaker might recognize it as a performance error—maybe they meant “lost.”
• A second language learner might genuinely be unsure of the correct past tense verb.

Understanding this difference helps us as teachers to respond appropriately in the classroom.

2. How Do Children Acquire Their First Language (L1)?

Interestingly, no matter where children grow up—across different cultures, socioeconomic backgrounds, or education levels—they tend to acquire language in similar, predictable stages. Most children reach full command of their mother tongue around age five (Kess, 1993). But how do they manage such a complex task without formal teaching?

Here’s a simple breakdown of the main stages in first language acquisition:

Stage	Age Range	What Happens
Pre-speech	2–4 months	Babies make sounds expressing comfort or discomfort; “vocal play” begins
Babbling	6–8 months	Repeated syllables, like “ba-ba” or “da-da”
One-word / Holophrastic	9–18 months	Single words express entire ideas (e.g., “milk” could mean “I want milk”)
Two-word stage	18–24 months	Simple two-word combinations (“mommy go,” “doggie big”)
Telegraphic / Early multi-word	24–30 months	Short sentences lacking function words (“want juice,” “go store”)
Later multi-word	30+ months	More complex sentences with grammar and vocabulary expansion

Imagine a baby saying “milk.” They might mean “I want milk” or “There’s milk,” depending on context. Sometimes they use a word too narrowly (underextension), or too broadly (overextension). For example, a toddler calling all four-legged animals “doggie.”

Babies start with sounds they can easily produce and gradually build up to sentences, much like learning to walk before running.

3. What Helps Children Acquire Language?

Caregivers naturally adjust how they speak to babies, a style often called motherese or infant-directed speech. This speech is slow, uses short sentences, higher pitch, and exaggerated vowels—all designed to help babies notice and learn language patterns (Lightbrown & Spada, 2006).

For instance, a mother might say, “Look at the biiig dog!” elongating the vowels to highlight important sounds. This style captures a baby’s attention and helps them differentiate sounds, recognize words, and even understand emotion through intonation.

Research confirms how crucial this input is:

• Babies exposed to repetitive language at 7 months tend to have larger vocabularies at 24 months (Newman, 2015).
• Clearer vowel sounds from mothers predict better vocabulary growth between 15-19 months (Kalasnikova, 2018).
• When mothers experience postpartum depression and speak in lower, less expressive tones, children’s language development suffers (Kaplan, 2012).
• Late talkers often receive less infant-directed speech and lower pitch from caregivers (D'Odorico & Jacob, 2006).

Babies are social learners. They prefer this kind of speech and use feedback from adults—who often repeat their attempts and expand on them—to build grammar and vocabulary naturally.

4. Cognitive Development and Language: How Are They Connected?

There’s an ongoing debate in psycholinguistics about how much general cognitive development influences language acquisition:

• Some say that children need certain cognitive abilities to build language skills.
• Others argue that language learning mechanisms are specialized and work independently.
• Noam Chomsky’s theory of Universal Grammar suggests children are born with an innate understanding of linguistic categories and rules common to all human languages.

While acquiring a first language tends to happen naturally, learning a second language usually requires conscious effort—like studying vocabulary and practicing grammar. Adults learning an L2 often need explicit teaching, repetition, and memorization, which children acquiring L1 don’t.

This leads to important differences between L1 and L2 acquisition.

5. Comparing First and Second Language Acquisition

What explains the differences between L1 and L2 acquisition? Several factors come into play:

• Age: There’s a “critical period” for language acquisition, roughly from birth to puberty (Lennenberg, 1967). Learning an L2 after this period might mean you never reach native-like proficiency, especially in pronunciation.
• Brain plasticity: Younger brains are more flexible and better at picking up sounds and grammar.
• Learning environment: L1 happens naturally in a rich, interactive home environment. L2 often happens in classrooms or formal settings.
• Motivation and emotions: Children learning L1 are driven by basic communication needs. Adults learning L2 may have different motivations—work, travel, school—which affect how much they practice and engage.
• Affective factors: Stress, anxiety, and attitudes toward the language can either help or hinder learning.

For example, a child growing up in a Spanish-speaking household will effortlessly pick up Spanish. Meanwhile, an adult learning Spanish as a second language in a classroom might struggle more with pronunciation and grammar.

6. The Critical Period Hypothesis (CPH)

Lennenberg (1967) proposed that there’s a critical period for language acquisition: if children don’t learn their first language before puberty, their ability to acquire it fully diminishes.

This idea has been extended to second languages, but the evidence is mixed.

• In favor: Hartshorne, Tenenbaum, and Pinker (2018) analyzed data from millions of English speakers and found that grammar learning ability declines after about 17 years old.
• Against: Yusa et al. (2011) showed that adults can still learn L2 with neural plasticity, suggesting some aspects of language learning don’t have strict critical periods.

So, the debate continues—and it’s important to consider individual differences.

7. Final Thoughts and Practical Reflection

As bilingual teacher trainees, understanding these stages and factors gives you powerful insight into how children and adults acquire languages. This knowledge will help you design better lessons, offer the right support, and appreciate the amazing, natural capacity humans have for language.

Ask yourself:

• Have you noticed students who struggle more with pronunciation than grammar? Could age or motivation be factors?
• How can you use motherese-like strategies—simple, clear, repetitive speech—to support beginners in your class?
• What role does emotion play in your students’ language learning?

Remember, language acquisition is a journey—sometimes smooth, sometimes challenging—but always remarkable.

References

Chomsky, N. (1994). The human language series.

Kess, D. (1993). Language development and acquisition.

Lightbrown, P. M., & Spada, N. (2006). How languages are learned (3rd ed.). Oxford University Press.

Newman, R. S. (2015). The role of repetition in early vocabulary acquisition. Journal of Child Language, 42(4), 842-865.

Kalasnikova, N. et al. (2018). Hyperarticulation and vocabulary growth in toddlers. Developmental Science, 21(3).

Kaplan, P. (2012). Maternal depression and infant language development. Journal of Child Psychology and Psychiatry, 53(6), 585-594.

D'Odorico, L., & Jacob, V. (2006). Infant-directed speech and late talkers. First Language, 26(2), 149-163.

Lennenberg, E. H. (1967). Biological foundations of language. Wiley.

Hartshorne, J. K., Tenenbaum, J. B., & Pinker, S. (2018). A critical period for second language acquisition. Cognition, 177, 263-277.

Yusa, N., Koizumi, M., Kim, J., et al. (2011). Neural plasticity in adult L2 learners. Journal of Cognitive Neuroscience, 23(10), 2716-2730.