Language: system of communication in which words and their written symbols combine in rule- governed ways that enable speakers to produce an infinite number of messages. Communication competence: ability to convey thoughts, feelings, intentions; important part of language learning is the development of this. Phonology: system of sounds that a particular language uses, includes phonemes: basic unit of a language"s phonetic system (smallest sound units that affect meaning) Phoneme example: changing cat to bat (initial phoneme) or bat to bit (middle phoneme) Phonological rules are generative: applicable beyond the cases on which they are based. For example, bnik is not a possible english word. Semantics: study of word meanings and word combinations. As children mature intellectually, their semantic knowledge continues to grow. Grammar: structure of a language, consists of two major parts listed below. Morphology: study of a language"s smallest units of meaning, or morphemes; like prefixes, suffixes, root words, etc.