CONVERSION [BrE], functional shift [AmE], also zero derivation. The use of a WORD that is normally one part of speech or word class as another part of speech, without any change in form: access, usually a noun, as a verb in You can access the information any time; author in They co-authored the book. Such shifts are impossible in highly inflected languages like Latin, which require a formal change, but are common in analytic languages like English. English love is both noun and verb, but in Latin the noun is amor, the verb amare. Conversion has for centuries been a common means of extending the resources of English and creating dramatic effects: ‘The hearts that spaniel'd me at heels’ (SHAKESPEARE, Antony and Cleopatra, 4. 13). Etymologically, such words as bang, crash, splash, thump were once primarily nouns or verbs, but functionally they favour neither word class. The process has been described as derivation without a change of form (zero derivation), but because no new word is formed it can equally well be regarded as syntactic (many words are not tied to one grammatical role) or semantic (as a sense relation on a par with synonymy).

It is often said that ‘there is no noun in English that can't be verbed’: bag a prize, doctor a drink, position a picture with care, soldier on regardless. However, some factors appear to get in the way of complete freedom to convert: (1) Morphology. It is unlikely that such a verb as organize will shift, because of its verbal suffix: no *Let's have an organize. (2) Inertia. Such a verb/noun contrast as believe/belief is unlikely to be overturned: no *This is one of my believes. (3) Utility. In law, there may be no need for jury to be other than a noun: no *I've juried several times. However, such a use cannot be ruled out. Striking one-off shifts often occur in fiction and journalism: ‘I decided she looked like the vamp in those marvellous Hollywood westerns, the lady who goes hipping and thighing through the saloon’ ( Susan Howatch, The Wheel of Fortune, 1984); ‘A formidable battery of legal grandees m'ludded and m'learned friended it out before Mr Justice Butt’ ( J. Keates, Observer, 18 June 1989). See JOURNALESE.