This paper presents a computer-assisted learning system of English prosody for French students. Our main goal is to provide learners with relevant feedback, based upon speech signal transformations and guided by a comparison between French and English prosodies. Considering that teachers should be given the possibility of customizing their courses, the main functions of WinSnoori for editing and modifying the signals has been ported in the form of active X controls. We present here these functions, a set of exercices conceived for the acquisition of English prosody, and give a concrete example illustrating our strategy.