Diphtongues vocaliques et diphtongues consonantiques

Within the syllable I look at the properties of diphthongs, defined as a glide and adjacent vowel. Both halves of a diphthong may occur within the nucleus of a syllable, or else only the vowel part is in the nucleus whereas the glide component functions as part of the onset or coda. This distinction is phonological and not necessarily phonetic and leads to a distinction between vocalic diphthongs and consonantal diphthongs. From this perspective, the diphthongs of English, French, and Spanish are examined. I provide criteria for distinguishing the two types of diphthongs. However, at times these criteria may be in conflict: the solution to this paradox is to be found through a constraint against syllables with no onset. A preliminary version of this study was presented at a conference dealing with syllables at the Université de Nantes, March 25-27, 1999. I thank the participants at that conference for their comments.