1. Used as a collective noun, pair is treated as a plural when it denotes two separate items and as a singular when it denotes a unit: so a pair of gloves, scissors, scales, shoes, trousers, etc. are singular whereas a pair of bachelors, dogs, idiots, rock-climbers, etc. (all taken from collocations occurring in OED2) would normally be plural. Examples: (singular)

• On the front of the radiator grille was mounted a pair of very large Cibie spotlights that dwarfed the standard headlamps —M. Booth, 1980

• To draw a heavy plough through wet clay soil, a pair of oxen yoked together was used —M. Graham-Cameron et al., 1984

• In addition to the various gripping wrenches, a pair of general-purpose pliers is always useful —D. Holloway, 1992

• (plural) The next pair of readings are concerned with what has perhaps been the single most salient political issue in British education in the twentieth century —M. Flude et al., 1989

• A pair of Pyracantha coccinea are placed strategically, one on either side of a cottage front door —Gardener, 1992.

2. However, the rule is not altogether rigid, and contrary examples can be found which do not seem ungrammatical:

• When you've lived on subsistence for two years what do you do when your shoes wear out, when you get a £100 fuel bill, when the washing machine breaks down, when a pair of children's shoes cost you more than you'd spend on your own? —B. Campbell, 1985

• One pair of ruby earrings are especially important —television news script, 1993.

In referring back to a ‘singular’ pair, the plural is normally used because it refers not to pair but to the following (plural) noun:

• She…handed me a pair of Japanese thongs. I slipped them on and felt the skin between my first two toes protest —H. Engel, 1981.

The standard plural form for more than one pair is (for example) two pairs of shoes, although two pair of shoes is used informally and in dialect use.
3. The phrase pair of twins is generally understood to mean a single set (the more usual word in the context of twins), not two sets:

• She gave birth to a pair of male twins, one of which was a stillborn with no malformations —Lancet, 1977.

Modern English usage. 2014.

(of the same kind or suited to each other), , / , , , / , / ,

Look at other dictionaries:

  • pair — pair …   Dictionnaire des rimes

  • pair — pair, aire (pêr, pê r ) adj. 1°   Égal, semblable, pareil ; ne se dit plus, en ce sens, que dans la locution : sans pair. •   Elles [deux chèvres] avaient la gloire De compter dans leur race, à ce que dit l histoire, L une certaine chèvre au… …   Dictionnaire de la Langue Française d'Émile Littré

  • Pair — (p[^a]r), n. [F. paire, LL. paria, L. paria, pl. of par pair, fr. par, adj., equal. Cf. {Apparel}, {Par} equality, {Peer} an equal.] [1913 Webster] 1. A number of things resembling one another, or belonging together; a set; as, a pair or flight… …   The Collaborative International Dictionary of English

  • pair — [per] n. pl. pairs or pair [ME paire < OFr < L paria, neut. pl. of par, equal: see PAR1] 1. two similar or corresponding things joined, associated, or used together [a pair of gloves] 2. a single thing made up of two corresponding parts… …   English World dictionary

  • pair — [peə ǁ per] verb [transitive] 1. COMMERCE if two companies, people, or things are paired, they are put into groups of two because they are connected in some way or will work together: • When the new products were paired, encouraging customer… …   Financial and business terms

  • pair up — ˌpair ˈup [intransitive/transitive] [present tense I/you/we/they pair up he/she/it pairs up present participle pairing up past tense …   Useful english dictionary

  • pair — PAIR, pairi, s.m. Titlu purtat de marii vasali ai regelui în Franţa şi în Anglia în evul mediu. ♦ Membru (pe viaţă) al uneia dintre cele două camere legislative din Franţa între 1815 şi 1848. ♦ Titlu de nobleţe în Marea Britanie, care conferă… …   Dicționar Român

  • Pair — Pair, v. i. [imp. & p. p. {Paired}; p. pr. & vb. n. {Pairing}.] 1. To be joined in pairs; to couple; to mate, as for breeding. [1913 Webster] 2. To suit; to fit, as a counterpart. [1913 Webster] My heart was made to fit and pair with thine. Rowe …   The Collaborative International Dictionary of English

  • pair — 〈[pɛ:r] Adj.; Roulett; bei Zahlen〉 gerade; Ggs impair [frz.] * * * pair [pɛ:ɐ̯ ] <Adj.> [frz. pair < afrz. per < lat. par, ↑ Paar]: (von den Zahlen beim Roulette) gerade. * * * pair   [pɛː …   Universal-Lexikon

  • Pair — 〈[ pɛ:r] m. 6; im alten Frankreich〉 Angehöriger des politisch bevorzugten Hochadels [frz. <lat. paria „Gleiches“] * * * pair [pɛ:ɐ̯ ] <Adj.> [frz. pair < afrz. per < lat. par, ↑ Paar]: (von den Zahlen beim Roulette) gerade. * * *… …   Universal-Lexikon