The study tests the hypothesis that phonetic reductions in spontaneous interaction contribute interpretive clues which aid in assigning different meanings to an ostensibly single grammatical pattern. We focus on two variants of insubordinate clauses introduced by jestli 'if/whether', each associated with a specific evidential meaning, as attested in the corpus of conversational Czech (Ortofon): a speaker's uncertainty about the truth of a given proposition vs. a speaker's certainty that the proposition is invalid.
Using phonetic feature analysis of the relevant words (jestli; nevím), we establish the degree of reduction by combining a word reduction rate with the number of segments and syllables that are actually pronounced. The analysis reflects a relationship between the degree of reduction and the functional split: highly reduced instances signal the interpretation of a speaker's uncertainty, while low reductions signal negative certainty.
These findings also suggest broader methodological and theoretical consequences, including the issue of adequate, multi-layered representational models of spontaneously produced language.