"The author has produced an excellent work on the diachrony and synchrony, on the meaning, distribution, and form of the progressive constructions in the Romance languages. This is a book that can be highly recommended to any linguist interested in periphrastic constructions, their origin and their grammaticalization, and in the interplay of aspect, actionality, and aktionsart." - Rolf Thieroff, Romance Philology 56/2003