Idiom variation and decomposability Part II: Variation in the noun phrase

Abstract Variant forms of idioms have been extracted from an American English corpus of 450 million words to test the idiom decomposition hypothesis, which proposes a dependence relation between the degree of idiom decomposability and the extent to which expressions are variable. The more decomposable the idiom is, the more flexibility it is expected to exhibit. In this second part of the study, morphological flexibility (number and determiner) as well as lexico- syntactic flexibility (the addition of various pre- and postmodifiers) of the noun have been assessed and related to three decomposability rankings. The results provide some support for the hypothesis. Of the individual flexibility dimensions, only number variation has been found to be significantly dependent on scalar decomposability. Of the overall measures, noun morphology and overall noun variation are significantly correlated. The relation between overall modifier variation and scalar decomposability is close to statistical significance, although premodifier and postmodifier variations taken separately do not show any dependence. None of the variation measures appear to be related to categorical decomposability.