Etymology: Variant of have v., arising through misapprehension of the verb (when occurring as a clitic) as showing of prep.

Etymology: Originally a low-stress variant of Old English æf (see below), cognate with Old Frisian af, of, Middle Dutch af, preposition (in a single attestation and in a small number of compounds), af, ave, of, aff, off, adverb (Dutch af, adverb), Old Saxon af, preposition (Middle Low German af, preposition, af, āve, preposition and adverb), Old High German aba, abe, ab, preposition and adverb (Middle High German abe, ab, ap, ave, preposition and adverb, German ab, adverb and preposition (as preposition now only in regional use, and in recent constructions before designations of place and time, the origins of which are variously explained)), Old Icelandic af, preposition and adverb, Norn (Shetland) ov, preposition and adverb, Old Swedish af, preposition and adverb (Swedish av), Danish af, preposition and adverb, Gothic af, preposition < the same Indo-European base as Sanskrit apa- (prefix) away, off, ancient Greek ἀπό off, away from, classical Latin ab off, away from.The form whence the Old English was immediately derived was af (as in Old Saxon, Old Icelandic, and Gothic). Like other prepositional adverbs, this developed two forms, according as it was stressed or stressless; in primitive Old English, æf and of . In historic times the stressed form appeared only in a few nominal compounds (e.g. ˈæfest evest n., ˈæfþunca displeasure, ˈæfweard absent), while the originally unstressed of survived, as inseparable verbal particle and preposition. In Old English this of began to be used also as a separable particle or adverb (as in infinitive of dōn , dative infinitive of to dōnne , past participle of(ge)dōn , imperative dō of , past tense he dyde of , in subordinate clause þe he of dyde ); and, as the adverb in this position always received the stress, this gave rise to a new stressed form. But to the end of the Middle English period, and often to 1600 or later, both unstressed and stressed forms were written of . The spelling off occurs sporadically in Old English and early Middle English, and from about 1400 it began to be used more often for the stressed form, to which it gradually came in course of the 16th cent. to be appropriated (though of was sometimes used even in the 17th cent.). This emphatic form was restricted to the adverb and those emphatic senses of the preposition which are akin to or derived from the adverb (e.g. be off! , get off the table! , hands off! , hands off the money! ); while the original spelling of pronounced /ɒv/, /əv/, remains for the weak senses of the preposition. Most orthoepists of the 16th and 17th centuries give the pronunciation of of with /v/ as the most common or only one, thus distinguishing it clearly from off ; /f/ is regularly given only in the words hereof , thereof , and whereof , in which of receives the main stress (see E. J. Dobson Eng. Pronunc. 1500–1700 (ed. 2, 1968) II. §4). Thus of and off now rank as different words. Between the 12th and the 15th centuries unstressed of before a consonant is occasionally further reduced to o . This form becomes rare by the early 16th cent., although the form a increases in frequency in the 15th and 16th centuries (see a prep.²). Early in the 17th cent. the reduced form o' becomes common mainly in colloquial usage (e.g. in Shakespeare and later dramatists); it has continued in regional and occasional poetic use, and has remained in fossilized expressions, chiefly o'clock adv. and certain traditional names and phrases, as John o' Groats , Jack-o'-lantern n., will-o'-the-wisp n., Tom o' Bedlam n. at Tom n.¹ Compounds 1b(b), etc. (formerly in other phrases, as man-o'-war (see man-of-war n.), mother-o'-pearl (see mother-of-pearl n., int., and adj.), and Isle o' Wight, in which of is now usually written). In Old English, the preposition is construed with the dative.