Content and function words in oral discourse

The goal of this paper is to verify whether there is an acoustic difference between a reduced form of the verb poder (po’) ‘to be able to’ and the noun pó ‘powder’ in Brazilian Portuguese oral discourse. The reduction of the verb occurs in contexts in which it is an auxiliary in periphrases formed with the infinitive. This process results in a form segmentally homonymous with the noun pó [‘pɔ]. As the literature states that function words are shorter in duration than content words, homonymy is expected to occur at the segmental, but not at the suprasegmental level. To verify this hypothesis, we analyzed data from Brazilian Portuguese spontaneous speech, selecting the parameters of normalized duration (in smoothed z-score), mean intensity, mean f0 of both [‘pɔ] and its contiguous words, and the mean frequency of the formants (F1 and F2) of the vowel of both the verb and the noun. Statistically significant results were found only for duration, confirming that the auxiliary verb (a function word) is shorter than the noun (a content word). It is suggested that the suprasegmental level, namely duration, is an important correlate in differentiation between two segmentally homonymous words but from different categories.