An affix is a morpheme that's attached to a word stem to form a new word. Affixes may be derivational, like English -ness and pre-, or inflectional, like English plural -s and past tense -ed. They are bound morphemes by definition; prefixes and suffixes may be separable affixes. Affixation is, thus, the linguistic process speakers use to form new words (neologisms) by adding sounds (affixes) at the beginning (prefixation), the middle (infixation) or the end (suffixation) of words. Positional ca… (More on Affix)