This essay contributes to the research on the emergence of tense/aspect morphology by reviewing the results and task conditions of studies supporting either the Aspect Hypothesis (AH) or the Default Past Tense Hypothesis (DPTH) for second language (L2) learners of Spanish. The AH has found that past marking emerges based on inherent aspectual categories (Andersen 1991; Andersen and Shirai 1994), and the DPTH proposes (Salaberry 1999, 2002, 2003, 2008; Salaberry and Ayoun 2005) that beginning learners of Spanish with first language (L1) English initially use perfective past marking as a default tense marker. The present study reviewed the results and task conditions of studies of beginning classroom learners of Spanish with L1 English that support either hypothesis. The review shows that many learners go through a stage of marking preterite regardless of lexical aspect particularly in tasks requiring an explicit focus on forms or in impersonal narratives. On the other hand, beginning learners show prototypical associations of preterite marking with telic predicates in open-ended tasks or personal narratives, and stronger associations of imperfect marking with state verbs especially in personal narratives.