“He'll Grow out of it Soon—Won't He?”—The Characteristics of Older Children's Speech When They Do—and Don't—Grow out of it

Speech sound disorder is a common reason for referral to speech and language therapy services in the early years. While for some children, their difficulties are transitory and they either respond to intervention or their difficulties resolve, for others, their speech sound difficulties evolve into persistent speech disorder (PSD). The purpose of this article is to provide information on the features of PSD and how to assess children with PSD in order to identify the full range and limits of their speech sound system. Reference is made to ALSPAC, a large longitudinal population study, regarding prevalence, possible subtypes, and risk factors for PSD.