The current study analyzes distributional frequencies of the Spanish Progressive construction ( ESTAR +Gerund) in a corpus of late-twentieth-century conversational speech in order to assess changes in structure and meaning. The analysis incorporates structural priming as a measure of analyzability and autonomy and utilizes both lexical and contextual measures of aspect to assess the construction’s preferred environment relative to its competing gram: the simple Present. Results of a multivariate analysis ( N =1,017) indicate that over the last 100 years, the construction has lost analyzability, further coalescing into a single grammatical unit. This new unit has also acquired the ability to express limited duration (progressive, continuous) aspect with stative as well as dynamic verbs, indicating the consolidation of the construction’s aspectual import. At the same time, its presence in extended duration contexts is attributed to strong effects of Progressive-Progressive priming and, to a lesser extent, licensing by a co-occurring temporal adverbial. By situating these results within the construction’s diachrony, it is concluded that the increased grammaticalization of the Spanish Progressive in the twentieth century, as assessed quantitatively, is markedly distinct from previous centuries.