Old English grammar

The grammar of Old English is quite different from that of Modern English, predominantly by being much more inflected. As an old Germanic language, Old English has a morphological system that is similar to that of the hypothetical Proto-Germanic reconstruction, retaining many of the inflections thought to have been common in Proto-Indo-European and also including characteristically Germanic constructions such as the umlaut.

Among living languages, Old English morphology most closely resembles that of modern Icelandic, which is among the most conservative of the Germanic languages; to a lesser extent, the Old English inflectional system is similar to that of modern German.

Nouns, pronouns, adjectives and determiners were fully inflected with five grammatical cases (nominative, accusative, genitive, dative, and instrumental), two grammatical numbers (singular and plural) and three grammatical genders (masculine, feminine, and neuter). First- and second-person personal pronouns also had dual forms for referring to groups of two people, in addition to the usual singular and plural forms. The instrumental case was somewhat rare and occurred only in the masculine and neuter singular. It was often replaced by the dative. Adjectives, pronouns and (sometimes) participles agreed with their antecedent nouns in case, number and gender. Finite verbs agreed with their subject in person and number.

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