This document discusses how knowing a word involves understanding its sound, meaning, morphological formation, and syntactic category and use. It provides examples of how verbs have related forms like talk/talks and can be preceded by auxiliary verbs. Nouns have singular and plural forms and can be preceded by articles. Identifying parts of speech involves looking at related forms and common syntactic patterns, like verbs occurring with auxiliaries and nouns taking articles. The document aims to describe the core components of lexical and morphological knowledge involved in fully knowing a word.