Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
dozen (adj., n.)
The noun dozen has two plurals: dozen and dozens. The inflected plural is used by itself and also modified by a prepositional phrase: Complaints came the next morning by the dozens. Dozens of people came to see us. When dozen is modified by a number, it takes the s-less form of the plural noun: Send me three dozen eggs. Normally the s-less plural is not followed by a prepositional phrase with of: Three dozen of linen napkins was once acceptable, but today Standard English says Three dozen linen napkins. Note, however, that with pronouns as objects of the preposition of, the construction is Standard (three dozen of these; two dozen of them), as it also is when these or those are determiners (three dozen of these cups; two dozen of those apples). After dozens, the of is Standard when there is no modifying number: dozens of linen napkins. See also PLURALS OF NOUNS.
