Central semantic of value adposition

Syntactic criterion

1. An adposition is an invariable morphological unit that relates, within a sentence, different syntactic constituents which have different syntactic functions or different semantic roles. In French, we only have the type-value preposition; prepositions introduce a NP, and this from a syntactic and semantic point of view.
   • appeler à la révolte
   • se diriger vers la sortie

Semantic criterion

1. We can distinguish semantically empty prepositions from semantically ``full'' prepositions. Semantically empty prepositions are strongly bound prepositions in the case of V, N, Adj complementation (``case markers''). Semantically empty prepositions are weakly bound prepositions in the case of V complementation, or unbound prepositions.

   Strongly bound prepositions:

   • appeler à la révolte
   • facile à apprendre
   • la direction du projet

   Weakly bound prepositions:

   • se diriger vers la sortie

   Unbound preposition:

   • travailler pour gagner la vie / goal
   • travailler pour la gloire / goal