In our PhD research (Van Goethem 2006), we have studied the relationship between prepositions and their preverbal counterparts. Following Amiot (2004, 2005), we claim that prepositions can undergo a grammaticalization process and develop into prefixes. This "prefixization" process can be determined on the basis of several parameters. On the morpho-syntactic level, preverbs can behave as adpositions or can develop a new "prefixal" behaviour. In L'avion survole actuellement les îles Baléares 'The plane is currently flying over the Balearic Islands', sur- interacts with two syntactic arguments, assuming the roles of trajector (l'avion) and landmark (les îles Baléares), which is the typical syntactic behaviour of adpositions. In other cases, the preverb is incidental to its base and can be considered more grammaticalized (e.g. Il a surestimé ses forces 'He has overestimated his forces'). Dutch presents a third preverbal construction type, which is not based on an adpositional construction, but which is the result of the reanalysis of a resultative adverbial predicate (with a prepositional homonym) (e.g. de soep opeten 'to eat up the soup'). These three construction types have a semantic counterpart: in the relational or predicative construction, the preverb mostly expresses the same meanings as its adpositional, resp. adverbial counterpart. In the "prefixal" construction type, however, it often develops new aspectual or evaluative meanings (e.g. excess meaning in surestimer). In the third place, we have noticed that on the comparative level, the study of the translation of preverbs is often indicative of their grammaticalization degree. The application of these three parameters on the preverbal use of sur, op, over 'on, upon, over'; contre, tegen 'against' and entre, tussen 'between' has led to some surprising findings. Firstly, we have noticed that the preverbal use of similar prepositions as sur and op is largely divergent. Secondly, French preverbs seem to be more grammaticalized, and hence closer to prefixes, ...