Derivational Affixes of English

Derivational affixes can be used to create many words. Unlike inflectional affixes, derivational affixes often change the grammatical category. In linguistics, derivation refers to the creation of a new word.

The affix -dom can attach to king to create the word kingdom. Since both words are nouns, the affix does not create a new grammatical category. However, the two words have distinct meanings. One refers to a person and the other to a place.

The affix -y attaches to nouns and creates adjectives. It is a very productive affix because it creates many words. They include cloudy, dirty, fussy, icy, lucky, rainy, snowy, stormy, sunny and windy.  

Another productive derivational affix is the prefix -un. It does not create a new grammatical category, but it creates a word that is opposite in meaning to the original. Examples include unfriendly, unhappy, unhealthy, unintentional, unkind, uninteresting, unlikely, unreliable, unsure and unusual.

The derivational suffix -ness is also very productive. It attaches to adjectives to create nouns. Examples include darkness, fitness, greatness, happiness, illness, kindness, sadness, shyness, sleepiness and weakness.

Derivational affixes are common in the formation of words in English. They can be prefixes and suffixes and they often change the grammatical category of the word. Derivational affixes can combine with inflectional affixes in the same word. In the word neighbourhoods, the derivational affix-hood is followed by the inflectional affix -s.