Re:It’s Hard to Learn French in Middle Age
by astrobe_ on Tuesday April 30, 2019 @03:05PM
(#19790879)
You are talking about a diaeresis [1]
For "rien" in particular, I'd say speakers can do that diaeresis as a sort of emphasis. For instance "Tu n'as rien fait! Rien! ("you did nothing! Nothing!"). The first "rien" can be said as a single-syllable world, while the second one can be pronounced as a two-syllables.
It also may be pronounced slightly differently in various places in France (regional accents).
I'm sure that's true, but I don't think it gives rise to any real doubt as to the syllable count. For example, you could stretch out the English word "near" into two syllables in very slow and deliberate speech, but it's definitely a monosyllabic word in most (possibly all?) varieties of English.