According to Wayne Weiten, author of Psychology: Themes and Variations, semantics is the large area of language concerned with understanding the meaning of words and word combinations. Weiten also states that “learning about this includes learning about various other things and what those words refer to,” (Weiten, 315). After phonemes and morphemes and semantics in the structure of language, syntax comes next. It is “a system of rules that specify how words can be arranged into sentences.” A sentence must contain a verb phrase and a noun phrase, Weiten concludes. Children who don’t learn language during their critical period lose the ability to learn language in the future.
According to Veronica Cullinan and Agata Vitale, authors of “The contribution of Relational Frame Theory to the development of interventions for impairments of language and cognition”, Relational Frame Theory has random and useful relational responding and has key information dealing with language development and acquisition.