English has eight inflectional affixes. They are affixes which have a grammatical function but do not change the class of a word. They always follow derivational affixes.
The word "king" can combine with the derivational affix -dom to create the word "kingdom." Though both words are nouns, they differ in meaning. One refers to a monarch and the other to a territory which a monarch rules over. However, the plural "kings" has an inflectional affix. The words "king" and "kings" only differ in number. Though "king" and "kingdom" are both nouns, many derivational affixes change the class of a word. For example, the word "windy" is composed of the noun "wind" and the affix -y. When the noun combines with the derivational affix -y, the result is the adjective "windy."
The eight inflectional affixes of English are the third person singular present -s, the past tense marker -ed, the continuous marker -ing, the past particle -en, the plural marker -s, the possessive marker -'s, the comparative suffix -er and the superlative suffix -est. Here are examples with the eight affixes:
1. She loves hockey.
2. He waited patiently.
3. They are watching TV.
4. I haven't eaten lunch yet.
5. The children ate all their vegetables.
6. Peter's car is new.
7. Peter's car is newer than mine.
8. Peter has the newest car here.
Modern English does not have many inflectional affixes. Earlier stages of English, Old English and Middle English, had more. In fact, a number of languages such as German and Spanish have more inflectional affixes than English. However, all languages have more derivational affixes.