The Basque verb possesses three non-finite participial forms, which are reminiscent of those habitually displayed by romance languages. However a closer scrutiny will unveil profound differences : (i) in this essentially modular grammar, the question of aspect, which is dealt with by non-finite verb forms, is entirely disconnected from that of valency, which is processed by the auxiliary ; (ii) the agglutinative morphology of the Basque verb originates the formation of a whole range of derived verb forms of all categories with no counterpart in romance languages. This study sketches the general principles along which the system is organized, making it possible to interpret the diversity of verb forms encountered in the terms of a limited number of constructional patterns.
