Inflection involves the addition of a bound morpheme or a change to the form of the word in order to change the grammatical function or meaning. For example, in English the base form of the verb drink can be changed by adding a suffix (-s for third person singular simple present, -ing for the present participle/gerund) or by changing it to drank (past simple) or drunk (past participle).
In English various grammatical classes may be inflected. Apart from verbs, others include:
- Many nouns form the plural by adding the plural suffix -s eg horse/horses . Others use -en eg. ox/oxen - and/or may involve a change of form child/children; mouse/mice.
- Adjectives may be inflected in various ways, eg: by adding a prefix such as un- to change the meaning to the negative - happy/unhappy; by adding suffixes to form different word classes - sad/sadly/sadness; by adding the suffixes -er or -est to form the comparative and superlative - fast/faster/fastest.
- Demonstratives are inflected to form the plural : this/these and that/those.