Terminology
The noun "scissors" is treated as a plural noun, and therefore takes a plural verb ("these scissors are"). Alternatively, this tool is also referred to as "a pair of scissors". In American English, "a pair" is singular and therefore takes a singular verb ("this pair of scissors is"). In British English, "a pair" does not take the singular ("this pair of scissors are"). The word shears is used to describe similar instruments that are larger in size and for heavier cutting. Opinions vary geographically as to the size at which 'scissors' become 'shears', but this is often at between six to eight inches in length.
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