Speech and language pathologists (SLPs) evaluate and treat children and adults with specific speech, language, and communication issues in order to help them speak as effectively as possible through speech and language therapy.A person is said to have a speech disorder if they have difficulties making speech sounds accurately or fluently. This refers to an issue with the actual production of sounds. When a person has issues comprehending people (receptive language) or expressing their thoughts, ideas, and feelings (expressive language), they are said to have a language disorder.