Language Disorders in Children: Developmental and Acquired Types

Last updated on:

November 5, 2025

Language is one of the most complex skills a child develops, and for most, it unfolds naturally over the first few years of life. But for a significant number of children, this process does not go as expected. Some struggle to acquire language from the very beginning, while others lose language skills they had already gained due to a brain injury or illness. Understanding these two distinct categories – developmental and acquired language disorders – is essential for parents, teachers, and anyone working with children. Together, they represent some of the most consequential communication challenges a child can face.

How language development typically unfolds
Developmental language disorder (DLD)
Causes of DLD
Characteristics of children with DLD
Acquired childhood aphasia
Causes of acquired childhood aphasia
Characteristics of acquired childhood aphasia
Recovery and prognosis
DLD vs. acquired childhood aphasia: key distinctions

How language development typically unfolds

Before examining what goes wrong, it helps to understand what typical language development looks like. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), the first three years of life are the most intensive period for acquiring speech and language skills, as the brain is developing and maturing rapidly during this time.

The process begins at birth with crying, the earliest form of communication. Between one and four months, infants begin cooing – soft, vowel-like sounds that signal contentment and social engagement. Yale School of Medicine notes that between four and eight months, a major milestone emerges: canonical babbling, where babies begin repeating consonant-vowel syllable strings. By around ten to fifteen months, most children produce their first recognizable words. Between eighteen and twenty-four months, children start combining two words together, and by age three, most are using full sentences and holding brief conversations.

These milestones form the baseline against which language disorders are identified. When a child’s development deviates significantly from this trajectory – either in timing, pattern, or quality – it warrants professional attention.

Developmental language disorder (DLD)

DLD is identified when a child has persistent problems with language development that continue into school age and beyond, without a clear explanation such as hearing loss, intellectual disability, or autism spectrum disorder. It is far more common than many people realize. Research published in Frontiers for Young Minds indicates that roughly one in every fourteen to fifteen children is affected – meaning in a typical classroom of twenty-eight students, approximately two children are likely to have DLD.

The disorder affects both the expressive side of language (putting thoughts into words) and the receptive side (understanding what others say). MedlinePlus notes that language disorders are not the same as delayed language: with delayed language, a child follows the usual developmental pattern but more slowly, whereas with a language disorder, the development itself is atypical – some skills may be present while others are absent or structured differently.

Causes of DLD

DLD rarely has a single, identifiable cause. The NIDCD explains that it results from complex interactions between genes and the environment that alter brain development, with the exact mechanisms still not fully understood. Genetic factors play a strong role – between 50 and 70 percent of children with DLD have at least one close family member who has also had language difficulties. Cleveland Clinic reports that environmental risk factors include premature birth, low birth weight, and nutritional deficiencies such as thiamine (vitamin B1) deficiency.

DLD can also occur alongside other neurodevelopmental conditions. A study in Frontiers in Pediatrics identifies neurological conditions such as hearing impairment, genetic syndromes (including Down syndrome and 22q11 deletion syndrome), and disorders like Autism Spectrum Disorder (ASD) and epilepsy as secondary causes of language delay. In these cases, the language difficulty is considered a consequence of the primary condition. Psychological factors, including extreme emotional deprivation, can further compound language difficulties, though they rarely act as sole causes.

It is important to note, as Stanford Children’s Health confirms, that growing up bilingual or multilingual does not cause DLD, and it is not harmful for children with DLD to learn multiple languages.

Characteristics of children with DLD

Researchers at Purdue University’s Child Language Research Lab describe a range of observable signs in young children with DLD. These typically begin with late onset of talking – children with DLD often say their first words later than peers. From there, the challenges can include limited vocabulary, difficulty constructing grammatically correct sentences, and trouble with conversational skills such as staying on topic or taking turns in dialogue.

Some children with DLD may exhibit echolalia – the repetition of words or phrases heard from others, without meaningful communicative intent – as well as neologisms, where they invent their own words in an attempt to fill vocabulary gaps. Auditory comprehension is frequently affected; a child may appear inattentive or confused not because of behaviour issues, but because they are genuinely struggling to process spoken language. Cleveland Clinic notes that children with DLD may avoid social situations because they feel awkward or embarrassed about their communication difficulties.

The academic consequences are significant. The NIDCD reports that by adulthood, people with DLD are six times more likely to be diagnosed with reading and spelling disabilities and four times more likely to have math disabilities compared to those without the disorder. DLD is not something most children simply grow out of – it is a lifelong condition that requires sustained support.

The DLD Project also highlights that DLD commonly co-occurs with ADHD, developmental coordination disorder, dyslexia, and dyscalculia, and that many affected children go unidentified and do not receive the specialist services they need.

Acquired childhood aphasia

While DLD is a disorder of language development, acquired childhood aphasia (ACA) is categorically different: it is the loss of language skills that a child had already developed, caused by damage to the brain. Children’s Hospital of Philadelphia defines it as a change in the way a child uses or processes language following a medical incident or injury, noting that it can make it hard for the child to understand what others say, what they read, or how to express their own knowledge.

A key diagnostic criterion is that the child must have already acquired some language before the injury occurs. As researchers in the field of ACA note, the condition is generally not diagnosed in children under the age of two, since sentence-level language has not yet emerged.

Causes of acquired childhood aphasia

Clinical literature on ACA indicates that it most commonly results from damage to the left hemisphere of the brain, particularly the left basal ganglia, thalamus, and surrounding subcortical areas. The Children’s Hospital of Philadelphia lists the primary causes as traumatic brain injury (TBI), stroke, brain tumours, encephalitis, and seizure disorders. Paediatric speech therapy sources note that traumatic brain injuries – from events such as motor vehicle accidents, falls from playground equipment, or similar blunt head trauma – are among the most frequent triggers of ACA.

A particularly notable form of ACA is Landau-Kleffner syndrome, a rare condition in which children who have been developing language normally progressively lose the ability to understand and use spoken language, associated with abnormal electrical activity in the brain during sleep. Research published in PMC explains that this syndrome involves acquired aphasia with convulsive disorder and a loss of previously acquired language skills, either suddenly or gradually.

Characteristics of acquired childhood aphasia

The language profile seen in ACA can vary considerably depending on the site and severity of the brain damage. ScienceDirect’s overview of childhood aphasia describes the condition as typically presenting with reduced verbal output, hesitancy, and articulation difficulties. Some children produce fluent speech that lacks coherent meaning, while others speak in short, effortful bursts with many pauses.

Specific difficulties include anomia (difficulty retrieving names of objects), impaired auditory comprehension, problems with repetition, and word-finding failures where a child knows what they want to say but cannot access the word. CHOP notes that in mild cases children may have word-finding difficulties only some of the time and still manage conversation, while in severe cases they may not be able to understand directions or produce more than a few words at a time. Contact, a UK charity supporting families with disabled children, also highlights that characteristics can include poor attention, problems repeating heard words, and difficulty understanding simple questions.

Recovery and prognosis

One key difference between ACA and adult aphasia is the role of neuroplasticity. The developing brain has a greater capacity to reorganize itself after injury – undamaged regions can take over some of the linguistic functions of the damaged areas, which is why children with ACA often show better recovery trajectories than adults. Clinical evidence suggests that children who develop aphasia following traumatic brain injury are more likely to achieve full language recovery than those whose aphasia results from stroke. However, prognosis varies widely by cause, severity, and how early speech-language therapy begins.

DLD vs. acquired childhood aphasia: key distinctions

Although both conditions involve significant language difficulties, they differ fundamentally in origin and clinical presentation. DLD is a developmental condition – language never builds correctly from the start, with no clear structural brain damage evident. ACA, by contrast, involves a regression: a child who was developing language normally experiences a neurological event that disrupts or destroys established language abilities. Researchers who have compared the two conditions point out that the neuroanatomical correlates differ, the assessment tools used differ, and the therapeutic approaches must therefore be tailored differently. In DLD, assessments focus on developmental milestones; in ACA, the focus shifts to identifying what skills have been lost relative to the child’s pre-injury baseline.

Early identification matters in both cases. Stanford Children’s Health emphasizes that children who begin therapy early consistently achieve the best outcomes – and that parents play a critical role by working with speech-language pathologists on language-building activities at home.

What do you think? If a child in a classroom is consistently quiet, avoids group discussions, or seems to not follow instructions, how might educators distinguish between a language disorder and a behavioural issue – and what early steps could make a real difference? Should language screening be a standard part of every child’s annual school health check, given how commonly DLD goes unidentified?

References

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Language Disorders in Children: Developmental and Acquired Types

Table of Contents

How language development typically unfolds 🔗

Developmental language disorder (DLD) 🔗

Causes of DLD 🔗

Characteristics of children with DLD 🔗

Acquired childhood aphasia 🔗

Causes of acquired childhood aphasia 🔗

Characteristics of acquired childhood aphasia 🔗

Recovery and prognosis 🔗

DLD vs. acquired childhood aphasia: key distinctions 🔗