Developmental Psycholinguistics: The study of language and its development in children, as seen from a psychological point of view.
Language Acquisition Device (LAD): Proposed biologically-based mental structure that theorists believe plays a major role in children's language learning. Linguist Noam Chomsky revolutionized the idea that an infant's innate ability to understand a language structurally, before actually being able to speak it, allows for the possibility that children can learn any language intuitively before a certain age.
One-Word Stage: The stage in a child's language development when the elemental aspects of speech have been mastered, and complete words are used to express relationships between people and objects. In other words, the understanding and use of words as symbols, usually at the end of a baby's first year.
Telegraphic Stage: The last stage in early language development, when a child begins to form simple sentences and maintains a cognitive word order that can be understood as reflecting a native language.
Two-Word Stage: The early stage of language development when a child begins to use phrases to express common functions, such as locating and naming objects, demanding and desiring things, questioning, modifying, and qualifying.
Universal Adaptability: In linguistics, the point (believed to be before the age of one) when an infant can distinguish sounds from any language and reproduce them. This flexibility is lost after the child begins to specialize in his or her native language.