Variability of be Prep frozen expressions

In an attempt to explore the adjectival/adverbial dichotomy of predicative prepositional phrases (PPP), we classified 400 English be Prep C expressions and examined four properties: (a) quantifying adverb insertion (e.g., how ahead of his time), (b) intensifier adverb insertion (e.g., very much in force), (c) left to noun modification (e.g., at-table conversations), and (d) loss of idiomaticity when followed by relative pronoun (e.g., in a jam that really worries you). We found that 70% of the expressions examined accept intensifier adverb insertion, thus confirming that most of the prepositional phrases can be considered qualifying, gradable, bona fide adjectives. Approximately 25% of the data also accept quantifying adverb insertion and 25% of the expressions are able to undergo left to noun modification. Expressions varied in their behavior from those that were very frozen to a small number of expressions (about 5% of the PPP examined) in which the supposedly frozen noun complement could be the antecedent of a following relative clause, but we were unable to establish any kind of coherent continuum of frozenness for the expressions under study. The data and examples in this article substantiate both the uncertainty of traditional grammatical categories with regards to PPP, as well as the blurred boundary between idioms and free expressions.