pluralisation

Pluralisation is the process by which a noun is marked to indicate two or more items. It is a basic feature of noun morphology in many languages and interacts with numerals, determiners, and verb agreement. In some languages plural is marked morphologically on the noun, while in others it is expressed syntactically or through separate words.

Most languages form plurals through one or more of these mechanisms: affixation (such as suffixes or prefixes), internal vowel changes (ablaut-like patterns), or suppletion where an unrelated word is used. Some languages have multiple plural forms depending on factors such as gender, case, or classifier systems. Others employ little or no noun-specific plural marking and rely on numerals or context to convey number.

In English, plural formation is largely regular: most nouns add a suffix such as -s or -es (cat/cats, bus/buses). Irregular plurals include man/men, child/children, foot/feet, mouse/mice, goose/geese. Some nouns have the same form in singular and plural (sheep, fish in many uses), while others have plural forms only in specific senses or with certain determiner contexts.

Cross-linguistically, some languages have no morphological plural marking (for example, certain analytic languages rely on numerals or measure words to indicate plurality). Others use extensive plural systems with distinct plural classes, nonconcatenative patterns, or suppletive roots. Pluralisation also interacts with other grammatical categories, such as noun class systems and agreement on adjectives or verbs. Zero plural and dual or trial number systems occur in some languages as well.