Developmental verbal dyspraxiaDevelopmental verbal dyspraxia (DVD), also known as childhood apraxia of speech (CAS) and developmental apraxia of speech (DAS), is a condition in which an individual has problems saying sounds, syllables and words. This is not because of muscle weakness or paralysis. The brain has problems planning to move the body parts (e.g., lips, jaw, tongue) needed for speech. The individual knows what they want to say, but their brain has difficulty coordinating the muscle movements necessary to say those words.
Morphology (linguistics)In linguistics, morphology (mɔrˈfɒlədʒi ) is the study of words, how they are formed, and their relationship to other words in the same language. It analyzes the structure of words and parts of words such as stems, root words, prefixes, and suffixes. Morphology also looks at parts of speech, intonation and stress, and the ways context can change a word's pronunciation and meaning. Morphology differs from morphological typology, which is the classification of languages based on their use of words, and lexicology, which is the study of words and how they make up a language's vocabulary.
EtymologyEtymology (ˌɛtɪˈmɒlədʒi ) is the scientific study of the origin and evolution of a word's semantic meaning across time, including its constituent morphemes and phonemes. It is a subfield of historical linguistics, philology and semiotics, and draws upon comparative semantics, morphology, pragmatics, and phonetics in order to construct a comprehensive and chronological catalogue of all meanings that a morpheme, phoneme, word, or sign has carried across time.
