Thus Tweedledum goes with Tweedledee , and spick with span . A person killed in a traffic accident in Oxford in September 1988 was described by a witness not merely as a bystander but as an innocent bystander .
Bystanders are almost always innocent .
These are just elementary examples of an adhesive process which is part of the natural machinery of the language. See siamese twins . The New Fowler's Modern English Usage 2. The Macmillan Encyclopedia 2001 3. The Concise Oxford Dictionary of Linguistics, Oxford University Press 5.