Telegraphic Speech: Telegraphic speech refers to the early two-word combinations used by toddlers during the later stages of language development. It consists of essential content words without grammatical markers.
Overextension: Overextension occurs when toddlers use a word too broadly and apply it to various objects that share some characteristics with the original referent.
Underextension: Underextension is the opposite of overextension, where a toddler uses a word too narrowly and applies it only to specific instances rather than generalizing its usage.