Speech-language pathology is a field of expertise practiced by a clinician known as a Speech-language pathologist (SLP), also called speech and language therapist, or speech therapist, who specializes in the evaluation and treatment of communication disorders and swallowing disorders.The components of speech production include: phonation, producing sound; resonance; fluency; intonation, variance of pitch; and voice, including aeromechanical components of respiration. The components of language include: phonology, manipulating sound according to the rules of a language; morphology, understanding and using minimal units of meaning; syntax, constructing sentences by using languages' grammar rules; semantics, interpreting signs or symbols of communication to construct meaning; and pragmatics, social aspects of communication.Swallowing disorders includes oropharyngeal and functional dysphagia in adults and children and feeding disorders in children and infants.