Affixes are lexical additions to the root of a word. The purpose is to either change the meaning or class of a word (derivational) or to modify a word to indicate its grammatical components and function (inflectional).
Let us explore this further:
The word "derivational" relates to something having been placed under a category, group, or classification. Hence, the affix is called derivational because the job of this particular lexical addition is to change the word class of the original root by making a completely different word.
Derivational and inflectional affixes are added to nouns, verbs, adjectives and adverbs. Examples of derivational affixes include:
For nouns: -ion, -ance, -ment, -ness
Example: kind- relates to categorizing (a kind of...)
while kindness- is a completely different word that means "a good nature". Notice how the derivational affix changed the word "kind", an adjective, into kindness, which is a noun.
Derivational affixes that create verbs are often en-, be-, de-, em-, and -ify...also, -ize, -en and -ate.
Ex: soft (noun) turns into soften (verb) with the affix -en.
Now, on to the inflectional affixes.
The word "inflectional" relates to expanding or changing the function of a word. Hence, the affix in this case is called inflectional because its task is to expand its grammatical function within the word.
[the] eight inflectional affixes ... depend on the function of a word in a sentence. (Mark Canada, University of North Carolina at Pembrooke)
Hence, inflectional affixes are the morphemes of the word that indicate whether the word is:
- singular or plural (for nouns)
- past, present, or progressive (for verbs)
- superlatives (for adjectives and adverbs)
- big-bigger-biggest (-er, -est are inflectional affixes)
- calls, called, calling (-s, -ed, -ing, are inflectional affixes)
- fox, foxes, fox's and foxes' are inflectional because they differentiate between singular/plural and possessives.
English has only eight inflectional affixes--that is, affixes that depend on the function of a word in a sentence. For example, the inflectional affix s on the end of pot makes the word plural. The remaining affixes in English are derivational affixes, which change the form or meaning of words. (Mark Canada)