Language delay involves delays in speech or language development. It occurs when a child develops language skills in the typical sequence but a slower than typical pace. Children with language delay may be slower: to understand words or phrases, to say their first words, to learn new words, and/or to combine words to make phrases. A language delay is qualitatively different from a speech or language disorder, which occur when language skills develop at a typical pace but with atypical features. For instance, some children with speech disorders find it difficult to enunciate certain word sounds.
Nevertheless, although they experience such pronunciation difficulties, children with speech disorders are often more adept than peers with language delays at understanding words and phrases well and at forming sentences of their own. Language delays are the most common developmental challenge and are believed to affect between 5 and 10 percent of all preschoolers. They are sometimes temporary and may resolve on their own with little specialist intervention. However, some language delays may be indicative of more serious underlying disability or developmental disorders, including hearing impairment, non-linguistic developmental delay, an autism spectrum disorder (ASD), or Down syndrome. Language delays may also cause behavioral problems in children who become frustrated by their inabilities to express their needs and wishes. Some recent research indicates that children who experience language delay may develop long-term emotional challenges stemming from their early difficulties with communication.