The hidden language disorder affecting up to one in 12 children

Developmental language disorder can affect learning, confidence and social development, but specialists say children are too often mistaken for being inattentive, lazy or less able.

Developmental language disorder, or DLD, affects far more children than many parents and teachers realise, yet it remains widely misunderstood. The condition can make it hard for children to express themselves, follow classroom instruction and keep up with lessons, even when their intelligence is entirely typical. Czech speech therapists say the scale of the problem is significant: DLD is thought to affect as many as 8% of children, a rate higher than autism and attention deficit hyperactivity disorder.

Experts say the disorder sits within the group of neurodevelopmental conditions and often appears alongside other difficulties. Barbora Richterová, chair of the Association of Clinical Speech Therapists, said children with DLD may also struggle with motor skills or speech fluency, while Veronika Včelíková of the Association of Speech Therapists in Education said the mix of symptoms differs from child to child. That variability is one reason the condition is frequently missed or mistaken for poor behaviour, laziness or low ability.

The signs are not always obvious. A child may have trouble understanding more complex sentences, finding the right word or grasping abstract concepts. Short-term verbal memory can also be affected, making it hard to hold spoken instructions in mind long enough to act on them. Richterová said children who are more severely affected may not understand individual words, while those with milder difficulties may understand words but not full sentences, which can make school life especially difficult. She added that many children learn to conceal the problem by pretending they have understood when they have not.

The effects extend well beyond language lessons. According to the specialists interviewed, DLD can affect performance in maths, physical education and any subject that depends on spoken directions. Repeated failure may lead to frustration, embarrassment and low self-confidence, and some children respond by becoming angry while others withdraw and speak less. As they grow older, some may develop anxiety, depression or social phobia.

Early diagnosis is seen as crucial. Richterová said children are often referred to speech therapists at around the age of two or two and a half, giving parents a chance to learn how best to communicate with them and support development. Včelíková said the language demands of school should not be limited to Czech lessons, because language runs through the whole day and every subject.

The challenge is not confined to the Czech Republic. The Cleveland Clinic says DLD affects about 7% of children in the United States, while the US National Institute on Deafness and Other Communication Disorders says roughly one in 14 kindergarten children is affected. Both institutions say the condition can interfere with speaking, listening, reading and writing, and both stress the importance of early support. British speech and language therapists have made the same point, warning that a “wait and see” approach can allow academic and social problems to deepen.

There is also a persistent myth that screens cause the disorder. Richterová said that is wrong. DLD is a neurodevelopmental condition linked in part to genetics and to differences in the brain networks that support language. Heavy screen use may worsen related issues such as inattention, but it does not explain the disorder itself. The broader lesson, experts say, is that the number of children affected has not suddenly risen; what is changing is the ability of schools and families to recognise the problem and respond to it properly.