This study examines jaw and tongue blade (TB) articulation of prominence in two English sentences (one with all low vowels, and one with all mid front vowels) by L1 and L2 (French) speakers of English. The results show that even though the phonological target vowels are kept constant in the sentence, the amount of jaw lowering as well as the corresponding tongue position in the sentences varies for each word. This is true for both L1 and L2 speakers. However, the patterns of the L2 speakers can be different from those of the L1 speakers ; for instance, the L1 speakers show rather consistent patterns of Low-High jaw position for each word in a phrase in these sentences, with a step-wise lowering at TB position and one word produced at the lowest jaw position in the utterance, whereas L2 speakers generally do not have a consistent word with the lowest jaw position