smallest units of meanings 

-its a word or part of a word that cannot be broken into smaller meaningful parts, prefixs, suffixes, and rootwords

rules by which words are arranged in sentences

-adjectives go before nouns

rules for how words can be organized with respect to meaning

-the bicycle talked the boy into buying a candy bar

rules for appropriate use of language in different context

-may I ave your crayon? (or) Gimmie a crayon!