"People use idioms to make their language richer and more colorful and to convey subtle shades of meaning or intention. Idioms are used often to replace a literal word or expression, and many times the idiom better describes the full nuance of meaning. Idioms and idiomatic expressions can be more precise than the literal words, often using fewer words but saying more. For example, the expression it runs in the family is shorter and more succinct than saying that a physical or personality trait 'is fairly common throughout one's extended family and over a number of generations.'" (Gail Brenner, Webster's New World American Idioms Handbook. Webster's New World, 2003) "If natural language had been designed by a logician, idioms would not exist." (Philip Johnson-Laird, 1993)
"Idioms, in general, are deeply connected to culture. . . . Agar (1991) proposes that biculturalism and bilingualism are two sides of the same coin. Engaged in the intertwined process of culture change, learners have to understand the full meaning of idioms." (Sam Glucksberg, Understanding Figurative Language. Oxford Univ. Press, 2001) Shakespeare's Idioms
"Shakespeare is credited with coining more than 2,000 words, infusing thousands more existing ones with electrifying new meanings and forging idioms that would last for centuries. 'A fool's paradise,' 'at one fell swoop,' 'heart's content,' 'in a pickle,' 'send him packing,' 'too much of a good thing,' 'the game is up,' 'good riddance,' 'love is blind,' and 'a sorry sight,' to name a few." (David Wolman, Righting the Mother Tongue: From Olde English to Email, the Tangled Story of English Spelling. Harper, 2010) Levels of "Transparency"
"Idioms vary in 'transparency': that is, whether their meaning can be derived from the literal meanings of the individual words. For example, make up [one's] mind is rather transparent in suggesting the meaning 'reach a decision,' while kick the bucket is far from transparent in...