Interactions between speech style and coarticulation are investigated by examining local, non-local, anticipatory and carryover contextual effects on vowels in two French corpora of conversational and journalistic speech. C-to-V coarticulation is analyzed on 22 k tokens of /i, E, a, u, ɔ/(/E/=/e, ɛ/) 50-to-80 ms long. Contextual effects are measured as F2 changes in relation to the adjacent consonant (alveolar vs. uvular) in CV1 and V1C sequences. V-to-V coarticula-tion is analyzed on 33 k V1C(C)V2 sequences with V1 = /e, ɛ, o, ɔ, a/ falling within the same range of duration, and V2 either high/mid-high or low/mid-low. Contextual effects are measured as F1 changes as function of V2 height. Results show more local C-to-V coarticulation in conversational than in journalistic speech, as previously found for other languages. Interestingly, this interaction is clearer for all vowels in V1C, whereas coarticulation in CV1 is affected by style for non-high vowels only. V-to-V coarticulation is also found in both corpora but is modulated by style only for mid-front vowels and in the opposite direction (i.e. more overlap in journalistic than in conversational speech). Findings are interpreted in light of dynamic models of speech production and of a phono-logical account of French V-to-V harmony.