An Introduction to French Pronunciation

Intonation 149
But if no syllable (other than the final one) in a rhythmic
group of three or more syllables would be capable of taking
a main stress, i.e. if it would not have been possible to divide
the group into two, then it is the last syllable but one that
represents the peak, e.g.:
Ils vous ont compris. Ce n’est pas vrai.
Il va répondre. Elle est charmante.
Je ne le crois pas. Il peut vous aider.
(The difference between these and the previous set of
examples is that, whereas each utterance in the previous
set could have been divided into two rhythmic groups, e.g. Je
pars | demain /ʒc pa:r | dcmh/, it would not be possible so to
divide Il va répondre and the other examples in this second set.)
20.3.3 Declarative sentences consisting of two rhythmic
groups having a rising intonation on the first group and a
falling intonation on the second, e.g.:
Je vais lui demander | de partir.
Il a répondu | tout de suite.
C’est tout à fait | différent.