Chapter 3 – Language Development in Children

Case Study

Minh is a 14-year-old student learning English in school. During speaking activities, he often makes grammatical mistakes and sometimes cannot express his ideas clearly. His teacher usually corrects him immediately, but Minh becomes nervous and speaks less. At home, Minh watches English videos and plays online games with international players, where he learns new words more naturally through interaction. Minh wonders why he feels more confident in some situations than in class. He wants to improve, but he does not know which kind of feedback helps him most.

Discussion

1. Why does interaction sometimes help and sometimes inhibit?
2. What parts of Minh’s environment support learning most?
3. What kind of feedback might help him without silencing him?
4. How do confidence, attention, and interaction connect?

Introduction

Language development in children is a gradual and dynamic process that begins in infancy and continues through adolescence. It involves growth in phonology, vocabulary, grammar, discourse, and pragmatic competence, all of which develop through the interaction of biological capacities and language experience. Development is broadly patterned, but individual children differ in rate and profile depending on input, cognition, and social interaction. Research therefore treats language development as both biologically prepared and environmentally shaped rather than as the product of a single factor alone (Hoff, 2013; Kuhl, 2010).

Children’s early language growth is often described in stages because certain milestones tend to appear in a broadly predictable order. However, these stages should be understood as descriptive tendencies rather than rigid boundaries. Some children move faster or slower than others, and development in comprehension often outpaces production. A useful developmental summary includes the prelinguistic period, babbling, one-word utterances, two-word combinations, telegraphic or early multiword speech, and later language development in the preschool and school years (Hoff, 2013; Brown, 1973).

Language development is also influenced by multiple contextual factors. Children benefit from rich and responsive language environments, especially when caregivers engage them in frequent, meaningful interaction. Differences in the quantity and quality of input, as well as opportunities for social engagement, are associated with differences in vocabulary and broader language growth. When delays occur, early identification and intervention are important, and evidence supports a range of responses including speech-language therapy and parent-mediated support (Hart & Risley, 1995; Law et al., 1998/2000).

Stages of Language Acquisition

1. Prelinguistic Stage

The prelinguistic stage begins at birth and extends through the first months of life. During this period, infants communicate through crying, eye gaze, facial expression, vocal play, and gesture before they produce recognizable words. Even in the first year, infants are actively learning about the sound structure of language. They discriminate speech sounds, attend to prosody, and begin to tune their perception to the language or languages in their environment. These early perceptual and social abilities provide the foundation for later word learning and speech production (Kuhl, 2010; Hoff, 2013).

Early communication is therefore not “pre-language” in the sense of being unimportant. Rather, it is the stage in which infants establish joint attention, recognize familiar voices, and begin to interpret communicative intent. These developments are crucial because later vocabulary and grammar grow out of the child’s ability to connect sounds, people, objects, and social meanings in interaction (Kuhl, 2010; Hoff, 2013).

2. Babbling Stage

Babbling typically becomes prominent in the second half of the first year. In this stage, infants produce repeated syllable-like sounds and experiment with the articulatory patterns that underlie speech. Babbling is universal, but research shows that it is also shaped by language experience, since infants begin to reflect features of the ambient language in their vocalizations. For this reason, babbling is now viewed as an important bridge between early vocal play and meaningful word production rather than as meaningless noise (Oller, 2000; Kuhl, 2010).

Babbling also matters developmentally because infants who engage more actively with speech sounds are practicing the motor and perceptual coordination needed for later spoken language. It is one of the clearest examples of how biological readiness and linguistic exposure work together in early development (Oller, 2000; Hoff, 2013).

3. One-Word Stage

Around the end of the first year and into the second, children begin to produce recognizable single words. These one-word utterances often function holophrastically, meaning that one word expresses a larger message such as a request, label, or comment. A child who says “milk” may be asking for milk, identifying it, or refusing it depending on context. This stage is significant because it marks the shift from vocalization to symbolic language use (Hoff, 2013; Fenson et al., 1994).

Vocabulary growth in this period is influenced by input and interaction. Children who hear more varied and responsive speech generally show faster lexical growth, although individual variation is expected. Early word learning is therefore tied not only to cognitive development but also to the richness of communicative experience (Fenson et al., 1994; Huttenlocher et al., 2010).

4. Two-Word Stage

The next broad stage is the emergence of two-word combinations, usually in the second year. At this point, children begin combining words to express relations such as possession, action, location, and recurrence, for example “mommy go” or “more juice.” These combinations are simple, but they show that children are beginning to organize meaning across words rather than treating each word as an isolated label (Brown, 1973; Hoff, 2013).

This stage is developmentally important because it marks the beginning of syntax. Even before children produce fully grammatical sentences, their word combinations reveal systematic patterns and sensitivity to meaning relations. Brown’s classic work showed that these early constructions are structured and developmentally informative rather than random pairings of words (Brown, 1973).

5. Telegraphic or Early Multiword Stage

As vocabulary expands, children begin producing longer utterances that contain the most semantically important words while often omitting function words and inflections. This is commonly described as telegraphic speech. Children may say forms such as “me want cookie,” which are not fully adult-like but clearly express complex intentions. At this stage, grammatical development accelerates, and children begin acquiring markers such as tense, plurality, and basic word-order regularities (Brown, 1973; Hoff, 2013).

Errors remain common, but these are now understood as evidence of active rule learning rather than failure. Children test patterns, overgeneralize forms, and gradually restructure their linguistic system as exposure and use increase. This makes the telegraphic stage a major transition from early phrase building to productive grammar (Brown, 1973; Clark, 2003).

6. Later Language Development

After the early multiword period, language development continues well beyond age three. In the preschool and school years, children expand vocabulary rapidly, refine morphology and syntax, develop narrative ability, and become increasingly skilled at adapting language to audience and context. They also develop metalinguistic awareness, allowing them to reflect on language, humor, ambiguity, and different registers of speech more explicitly. For this reason, later language development should not be treated as a single “mature” stage that begins in toddlerhood, but as a long period of continuing growth across childhood and adolescence (Clark, 2003; Hoff, 2013).

This later development is shaped by schooling, literacy, peer interaction, and continued language exposure. Children learn not only how to form grammatically complex sentences but also how to explain, persuade, narrate, and participate effectively in varied social settings. Language development therefore remains closely tied to both cognitive growth and social experience long after the earliest stages are complete (Clark, 2003; Hoff, 2013).

Factors Influencing Language Development

Research consistently shows that language development is influenced by biological, environmental, and interactional factors. Infants come prepared to attend to speech, but development depends heavily on experience with meaningful language in social contexts. Input quantity matters, but input quality and conversational responsiveness also matter because children learn language through participation as well as exposure (Kuhl, 2010; Hoff, 2013; Hart & Risley, 1995).

Social interaction is especially important because language is learned in relationships. Caregiver talk, turn-taking, joint attention, and opportunities to hear and use words in context all support development. Differences in these experiences help explain why children vary in vocabulary size and broader language growth even when they follow the same general developmental sequence (Hart & Risley, 1995; Huttenlocher et al., 2010).

Interventions for Language Delays

When language delays are present, early intervention is important. Evidence from systematic reviews indicates that intervention can support children’s speech and language outcomes, especially when support is timely and matched to the child’s needs. Interventions may involve direct work with speech-language professionals, parent-implemented programs, or combined approaches that strengthen everyday language interaction as well as targeted skill development (Law et al., 1998/2000).

Parent involvement is particularly significant because children’s everyday interactions provide repeated opportunities for language learning. For this reason, effective intervention often includes helping caregivers use more responsive, language-rich communication strategies in daily routines rather than relying only on isolated therapy sessions (Law et al., 1998/2000; Hoff, 2013).

Factors That Influence Language Development

Language development is shaped by the interaction of biological predispositions and experience. Children are born with powerful capacities for attending to speech, but the growth of vocabulary, grammar, and communicative skill depends heavily on the linguistic and social environments in which they develop. For this reason, current research typically explains language development through the combined influence of genetic, environmental, and social factors rather than through any single cause alone (Hoff, 2003; Kuhl, 2010; Huttenlocher et al., 2010).

Genetic Factors

Genetic factors contribute to individual differences in language development, especially in the risk for language-related difficulties. Bishop (2002) argues that language impairment often runs in families, which supports the view that heritable influences are involved in language outcomes. However, the genetic contribution is complex rather than deterministic, and it does not imply that any single gene directly controls normal language development. Instead, genes are better understood as part of a broader developmental system that interacts with experience (Bishop, 2002).

Research on specific genes has strengthened this view. Work on FOXP2 showed that mutations affecting this gene are associated with severe speech and language difficulties, highlighting the importance of neurobiological foundations in language development (Vargha-Khadem et al., 2005). Other studies have also linked variation in CNTNAP2 to early language outcomes in the general population, suggesting that some genetic influences are relevant not only in clinical groups but also in typical development (Whitehouse et al., 2011). At the same time, these findings do not support a simplistic “language gene” account; they show that biological influences matter, but always within a wider developmental context (Vargha-Khadem et al., 2005; Whitehouse et al., 2011).

Environmental Factors

Environmental factors strongly influence how quickly and how well children develop language. One of the clearest findings in the literature is that children benefit from rich, frequent, and varied language input. Hoff (2003) found that socioeconomic differences in children’s early vocabulary growth were mediated by differences in maternal speech, showing that language experience helps explain developmental variation. Similarly, Huttenlocher et al. (2010) showed that the diversity of caregiver speech predicts later diversity in children’s vocabulary and syntax. These findings support the view that language development depends not only on how much language children hear, but also on the richness and structural variety of that input (Hoff, 2003; Huttenlocher et al., 2010).

Environmental effects are also visible in early language processing. Weisleder and Fernald (2013) showed that variation in the amount of child-directed speech was associated with differences in infants’ language-processing efficiency and vocabulary growth. This means that everyday input does not simply expose children to words; it also strengthens the processing skills that support later learning. Thus, language-rich environments support development by providing both exposure and opportunities to build efficient comprehension systems (Weisleder & Fernald, 2013).

Social Factors

Language develops in social interaction, not in isolation. Children learn language through back-and-forth exchanges with caregivers and others who respond to their attention, vocalizations, and communicative attempts. Tamis-LeMonda et al. (2001) found that maternal responsiveness predicted the timing of children’s language milestones, even after accounting for children’s own observed behavior. This supports the view that responsive interaction is not just helpful but developmentally significant for early expressive language growth (Tamis-LeMonda et al., 2001).

Social factors also include conversational turn-taking and participation in multilingual settings. Weisleder and Fernald (2013) showed that speech directed to the child matters more than background speech, underscoring the importance of direct interaction. In addition, exposure to more than one language can shape children’s opportunities for language growth in distinctive ways. Byers-Heinlein and Lew-Williams (2013) note that early bilingual development is a normal developmental pathway, but outcomes depend on the amount and quality of exposure to each language. Social experience therefore affects language development through responsiveness, conversational structure, and the linguistic communities in which children participate (Weisleder & Fernald, 2013; Byers-Heinlein & Lew-Williams, 2013).

Language Acquisition and Age: Critical Period Hypothesis

Age has long been considered an important factor in language acquisition. Lenneberg (1967) proposed the Critical Period Hypothesis, arguing that language learning is biologically constrained and most effective during early development. Later research extended this discussion to second language acquisition and generally found strong age effects, especially in pronunciation and ultimate attainment. However, contemporary work treats the critical period less as a rigid cut-off than as evidence that language learning changes with maturation and experience (Lenneberg, 1967; Johnson & Newport, 1989; Flege et al., 1999).

Ages 0–3

The first three years of life are especially important for language development because infants rapidly tune their perception to the sounds and patterns of the languages they hear. Kuhl (2010) shows that early exposure shapes neural circuitry for speech processing within the first year of life. During this period, children move from broad phonetic sensitivity to increasing specialization for the ambient language, while also beginning to acquire words and basic communicative routines. Early development in this age range is therefore closely tied to brain plasticity, speech perception, and social interaction (Kuhl, 2010).

Research also shows that disparities in language processing and vocabulary can emerge very early. Fernald et al. (2013) found that differences associated with socioeconomic context were already evident at 18 months and widened by 24 months. This makes the period from birth to age three especially important for providing rich language exposure and responsive interaction (Fernald et al., 2013).

Ages 4–6

Between ages four and six, children typically expand vocabulary rapidly, refine grammar, and develop the foundations of phonological awareness and early literacy. This period is important not because language suddenly begins here, but because oral language increasingly connects to literacy-related skills such as sound awareness, narrative ability, and print knowledge. Major reviews of early literacy development conclude that high-quality early language and literacy experiences in the preschool and kindergarten years are strongly associated with later reading success (Snow et al., 1998; National Early Literacy Panel, 2008).

Ages 7–12

Children in middle childhood remain highly capable language learners, but age-related differences begin to matter more clearly in some domains. Johnson and Newport (1989) found that earlier exposure to a second language was associated with higher grammatical attainment, especially before puberty. Similarly, Flege et al. (1999) found strong age effects in pronunciation, with foreign accent increasing as age of arrival rose. These studies suggest that children between roughly seven and twelve can still make strong progress, but age-related constraints become increasingly visible, especially in phonology (Johnson & Newport, 1989; Flege et al., 1999).

Ages 13–18

Adolescents are still able to learn language successfully, but the pattern of learning differs from that of younger children. Research on age effects suggests that learners who begin later are less likely to achieve native-like pronunciation and may show greater variability in ultimate grammatical attainment than earlier starters. At the same time, adolescents retain substantial learning capacity and can make major gains, particularly when they receive sustained exposure and use the language meaningfully. Thus, adolescence should not be treated as too late for language learning, but as a period in which age-related constraints coexist with strong cognitive and educational resources for learning (Johnson & Newport, 1989; Flege et al., 1999).

Interactional Modifications

In second language acquisition, interactional modifications refer to the adjustments speakers make during communication to maintain understanding and support meaning negotiation. These modifications include repetition, clarification requests, confirmation checks, recasts, and other conversational moves that arise when communication difficulty occurs. Rather than simply simplifying language, interactional modifications help learners notice problematic forms, obtain clearer input, and participate more actively in meaning-focused interaction (Long, 1983; Mackey & Philp, 1998). 

Long (1983) argued that conversational interaction is important not only because it exposes learners to input, but because it makes input more comprehensible through negotiation. From this perspective, the value of interaction lies in the collaborative work speakers do to repair misunderstanding and keep communication moving. Later research further showed that negotiated interaction can contribute to development when learners are pushed to process language more carefully and respond to feedback during communication (Long, 1983; Mackey & Philp, 1998). 

However, interactional modifications are not equally effective in all forms or contexts. Their value depends on factors such as learner proficiency, task type, salience of the target form, and whether learners actually notice the modified input or feedback. For this reason, SLA research generally treats interactional modification as beneficial, but not as automatically sufficient for learning in every case (Mackey & Philp, 1998; Lyster & Mori, 2006). 

Feedback

Feedback is a central mechanism through which learners receive information about the accuracy, appropriateness, or comprehensibility of their language use. In SLA, feedback is especially important because it can draw learners’ attention to gaps between their current interlanguage and the target language. Research on corrective feedback has examined a range of feedback types, including explicit correction, recasts, clarification requests, metalinguistic feedback, elicitation, and repetition (Lyster & Ranta, 1997; Ellis, 2009). 

One of the most influential studies in this area is Lyster and Ranta (1997), who proposed a taxonomy of oral corrective feedback and examined how different feedback types related to learner uptake. Their findings showed that feedback does not function as a single uniform phenomenon; some forms, such as prompts and elicitation, may encourage learners to self-repair, while recasts may be less salient unless learners recognize them as corrective. This helped establish that feedback effectiveness depends not only on whether correction is provided, but also on how it is delivered and interpreted (Lyster & Ranta, 1997). 

Research has also shown that recasts can support development under some conditions. Mackey and Philp (1998), for example, found that intensive recasts in conversational interaction were associated with gains in question development for learners who were developmentally ready. Similarly, Lyster and Mori (2006) argued that the effectiveness of feedback depends partly on instructional context, proposing the idea of instructional counterbalance to explain why more implicit or more explicit feedback may work differently across settings (Mackey & Philp, 1998; Lyster & Mori, 2006). 

Ellis (2009) emphasizes that corrective feedback should not be reduced to a simple choice between explicit and implicit correction. Its effects depend on timing, learner readiness, pedagogical goals, and the opportunities learners have to respond to it. A balanced conclusion, therefore, is that feedback is an important support for language development, but its value depends on how well it engages learners’ attention and encourages further processing of form in meaningful communication (Ellis, 2009). 

Problem-Solving Task

Minh is improving his English through online games, videos, and classroom lessons, but he still feels nervous when his teacher corrects his mistakes in front of others. In class, he often stops speaking after receiving direct correction, even though he wants to improve. Outside class, he learns more confidently through interaction with other players and by listening carefully to how they speak.

As a group, discuss how Minh’s teacher can help him develop both accuracy and confidence. Decide which kinds of interactional modifications and feedback would be most effective for him. Should the teacher use recasts, clarification requests, elicitation, or explicit correction? Explain why. Then design a short classroom plan that supports Minh’s speaking development without reducing his motivation.

Group Task

1. Decide which kinds of feedback best balance accuracy and confidence.
2. Choose among recasts, clarification requests, elicitation, and explicit correction.
3. Design a short classroom plan that keeps Minh speaking while still supporting improvement.

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Case Study Minh is a 14-year-old student learning English in school. During speaking activities, he often makes grammatical mistakes and sometimes cannot express his ideas clearly. His teacher usually corrects him immediately, but Minh becomes nervous and speaks less. At home, Minh watches English videos and plays online games with international players, where he learns…