Language disorder is a neurodevelopment condition with onset during childhood development. More specifically, classified as a communication disorder, the core diagnostic features of language disorder are difficulties in the acquisition and use of language due to deficits in the comprehension or production of vocabulary, sentence structure, and discourse. The language deficits are evident in spoken communication, written communication, or sign language.

Language learning and use is dependent on both receptive and expressive skills. Expressive ability refers to the production of vocal, gestural, or verbal signals, while receptive ability refers to the process of receiving and comprehending language messages. Language skills need to be assessed in both expressive and receptive modalities as these may differ in severity. For example, an individual’s expressive language may be severely impaired, while his receptive language is hardly impaired at all.

More specifically, according to the DSM-5 (2013), deficits in comprehension or production can include the following:

  1. Reduced vocabulary (word knowledge and use).
  2. Limited sentence structure (ability to put words and word endings together to form sentences based on the rules of grammar and morphology).
  3. Impairments in discourse (ability to use vocabulary and connect sentences to explain or describe a topic or series of events or have a conversation).

The language ability must be sub par for the individual’s age, resulting in functional impairment in school performance, when communicating with peers and caregivers, and participating in social settings broadly.

The difficulties are not attributable to hearing or other sensory impairment, motor dysfunction, or another medical or neurological condition and are not better explained by intellectual disability or pervasive, non-language specific (global) developmental delay.

This entry has been updated in accordance with (2013) DSM-5 criteria/classification; diagnostic code: 315.32.