This paper deals with one of the most problematic aspects of the prepositional complement in Spanish-the semantic role of the preposition. We have examined some space and notional structures of the verb of motion 'meter (en)', included in the 'Corpus de la variedad juvenile universitaria del espanol hablado en Alicante'. This analysis will permit us to check if the semantics of the preposition is a good criterion to establish some differences between 'aditamento' and 'suplemento'. Finally, we will conclude by showing that the substitution of the preposition by other prepositional elements depends on the semantics (physical or abstract) of the prepositional complement. (LLBA 2003, vol. 37, n. 4)