MORPHOLOGY: study of the formation of words.

- LEXICON : a "mental lexicon" in which the phonological form of a word is represented associated with its lexical category.
(e.g. table-noun)

- MORPHEMES : basic units of meaning that words are made
up of
e.g. BOOKS book: morpheme -s: morpheme

- MORPHOLOGICAL RULES : tell us how these units combine to form words

- SIMPLE WORDS : morphemes that can be words by themselves, also called free morphemes
e.g. book

- COMPLEX WORDS: words that are formed by combining a
BASE/ROOT (the form to which an affix is added) with one or more AFFIXES, also called bound morphemes
e.g.: BUILD + -ER
     Base/root  affix