Speech-language pathologist:
A specialist who evaluates and treats communication disorders and swallowing problems.  
A speech-language pathologist is sometimes called a speech therapist or speech pathologist.

Speech and language pathology specialize in Speech disorders and Language disorders.

The main components of speech production include: phonation, the process of sound production; resonance, opening and closing of the vocal folds; intonation, the variation of pitch; and voice, including aeromechanical components of respiration.

The main components of language include: phonology, the manipulation of sound according to the rules of the language; morphology, the understanding and use of the minimal units of meaning; syntax, the grammar or principles and rules for constructing sentences in language; semantics, the interpretation of meaning from the signs or symbols of communication; and pragmatics the social aspects of communication.^[1]

Developmental Progress Chart

Speech/Language Milestone Chart