Word class:

LEXICAL WORDS (open class)	

(nouns, adjectives, adverbs, verbs)

FUNCTION WORDS (closed class)

(prepositions, conjunctions, numbers, articles, pronouns,
etc.)

Words can be:
fl
a) derived (changes the word class, e.g. teach vs. teacher)
b) inflected (does not change the word class, e.g. strong
vs. stronger)
c) compound (contains two free morphemes, e.g.
classroom, homework)
Words consist of morphemes (smallest meaningful parts of
words)

Two types of morphemes:

1) FREE (single word)
2) BOUND: a) derivational, b) inflectionalfiffiflffi
a) derivational morphemes (system of prefixes and
suffixes) e.g. un-deni-able, im-possible, in-advertent-ly,
teach-er etc.)
b) inflectional morphemes (suffixes -ed, -er, -ing, -s) e.g.
work vs. worked, car vs. cars)