Developmental language transtorno is characterised by persistent deficits in the acquisition, understanding, production or uso of language (spoken or signed), that arise during the developmental period, typically during early childhood, and cause significant limitations in the individual’s ability to communicate. The individual’s ability to understand, produce or uso language is markedly below what would be expected given the individual’s age. The language deficits are not explained by another neurodevelopmental transtorno or a sensory impairment or neurological condition, including the effects of brain injury or infection.