This paper is a follow-up study on the issue of L2 inner speech as it manifests in mental rehearsal among advanced L2 learners. The purpose of the study was to find out to what extent advanced L2 learners experience inner speech as mental rehearsal and to identify some of the characteristics and functions of such inner speech. Results show that advanced L2 learners experience inner speech in the second language to a great extent and that the frequency of L2 inner speech increases with proficiency. Advanced L2 learners, however, report using less inner speech than lower level learners for certain aspects of rehearsal, such as planning texts, self- and other-evaluation, storage and retrieval, self-instruction, and language play. It is argued that inner speech in the L2 is a developmental phenomenon associated with spontaneous rehearsal in the early stages ofL2 acquisition and with verbal thinking in the more advanced stages.