French and Dutch preverbs in contrast

French sur and Dutch op (“on, upon”) can be a considered matching pair when they are used as prepositions: e.g. le livre sur la table/het boek op de tafel (“the book on the table”). However, used as prefixes, or in particular as preverbs, the similarities between sur- and op- seem to be much weaker. Instead, sur- corresponds more often to over-: e.g. surestimer quelque chose/iets overschatten (“to overestimate something”). From the analysis of a bilingual dictionary, we will investigate this phenomenon. At a morpho-syntactic level, on the one hand, we will show that French and Dutch preverbs appear in different types of constructions. At the semantic level, on the other hand, we will demonstrate that prepositions in preverbal use can develop new, often aspectual, meanings, but that this re-semanticization process does not necessarily follow the same paths in French and Dutch.