Our study focuses on the issue of prosodic annotation and of the prosody ~ syntax interface in conversation and is based on a large corpus of conversational speech in French. The results of inter-transcriber agreement tests show that two expert transcribers are consistent in their labeling of prosodic phrasing and the consistency is well above the chance. A qualitative analysis reveals transcribers' individual strategies, namely in reference to Intermediate Phrases sometimes found for French in specific intonation patterns. The syntactic division of the corpus both in terms of syntactic chunks and in terms of pseudo-phrases is further analyzed in its interaction with the distribution of major prosodic breaks. In more than 60% of cases the boundaries of the pseudo-phrases co-occurs with the boundaries of major prosodic units (Intonational Phrases, IPs). At the same time, 50% of IP boundaries are aligned with smaller syntactic constituents. On the other hand, in our study beginnings of intonational phrases are more often misalign with syntactic constituent boundaries than their ends. We discuss as well the issue of conversational corpus annotation in terms of prosodic units, given specific constraints on planning and execution in spontaneous speech.