When used without a modifier, pairs is the only possible plural: Pairs of skaters glided over the ice. When modified by a number, pairs is the more common form, especially referring to persons: Six pairs of masked dancers led the procession. The unmarked plural pair is used mainly in reference to inanimate objects or nonhumans: He has three pair (or pairs) of loafers. Two pair (or pairs) of barn owls have nested on our property. Pair signifying two individuals can take either a singular or plural verb, but it is usually followed by a plural verb and referred to by a plural pronoun: The guilty pair have not been seen since their escape. In the sense “a set or combination of more than two objects forming a collective whole,” pair occurs chiefly in fixed phrases: a pair of beads; a pair of stairs. This use is now somewhat old-fashioned. See also collective noun, couple.