suffixation

Suffixation is a morphological process in which a suffix, a bound morpheme, is attached to the end of a word stem to form a new word or to indicate grammatical information. It is a type of affixation, contrasting with prefixation (affixes at the beginning) and, in some languages, infixation (affixes inserted inside the base).

Suffixes can be derivational, creating new words and often changing the word’s part of speech, or inflectional, providing grammatical information without changing core meaning. Productivity varies by suffix and language; some suffixes are highly productive, others occur mainly in limited contexts or in borrowed items.

Examples in English include derivational suffixes such as -ness (happiness from happy), -able (readable from read), -ment (movement from move), and -er (teacher from teach). Inflectional suffixes include -s for plural (cats), -ed for past tense (walked), -ing for participles (singing), and -er or -est for comparison (faster, fastest). Allomorphy can affect pronunciation, as with plural endings that alternate in sound depending on the base form.

Across languages, suffixation is widespread. In agglutinative languages such as Turkish and Finnish, long chains of suffixes encode numerous grammatical categories; in fusional languages, a single suffix may carry multiple features. Suffixation interacts with phonology and orthography, occasionally triggering consonant or vowel adjustments at the boundary between stem and suffix.

In summary, suffixation is a central mechanism of word formation and grammatical marking, shaping how roots are extended, modified, and connected within sentences.