language spoken and written in England before 1100; it is the ancestor of Middle English and Modern English. Scholars place Old English in the Anglo-Frisian group of West Germanic languages.

Four dialects of the Old English language are known: Northumbrian in northern England and southeastern Scotland; Mercian in central England; Kentish in southeastern England; and West Saxon in southern and southwestern England. Mercian and Northumbrian are often classed together as the Anglian dialects. Most extant Old English writings are in the West Saxon dialect; the first great period of literary activity occurred during the reign of King Alfred the Great in the 9th century.

In contrast to Modern English, Old English had three genders (masculine, feminine, neuter) in the noun and adjective, and nouns, pronouns, and adjectives were inflected for case. Noun and adjective paradigms contained four cases—nominative, genitive, dative, and accusative—while pronouns also had forms for the instrumental case. Old English had a greater proportion of strong verbs (sometimes called irregular verbs in contemporary grammars) than does Modern English. Many verbs that were strong in Old English are weak (regular) verbs in Modern English (e.g., Old English helpan, present infinitive of the verb help; healp, past singular; hulpon, past plural; holpen, past participle versus Modern English help, helped, helped, helped, respectively).