Abstract
Using quantitative corpus evidence from different periods, the present article analyzes the emergence and diachronic development of the Spanish time constructions (clausal and adverbial) involving contemporary hacer ‘make’ and earlier haber ‘have’. The obtained data, as well as cross-linguistic evidence, suggest that the clausal construction must have been the source of the adverbial one. A proposal is presented that could explain that development. The data show, in addition, that the grammatical properties and usage patterns of the clausal and adverbial constructions were very similar until the 16th century but have been diverging ever since. This divergence coincides with an exponential increase in the textual raw frequency of the adverbial construction, where word order fixation, erosion of the inflectional morphology and a change in the possibilities for time adjunction among others are found to occur at around the same time. This points towards a desentencialization, loss of inner structure and grammaticalization of the adverbial construction in those periods.