Development of Brazilian Portuguese by an Argentinian learner: An Analysis of Stressed Vowels in Spontaneous Speech Productions via Complex Dynamic Systems Theory

Grounded in the theoretical-methodological perspective of CDST - Complex Dynamic Systems Theory (De Bot, 2015; Larsen-Freeman, 2017; Verspoor, De Bot; Lowie, 2011, among others), this article discusses the developmental trajectory of stressed oral vowels in Brazilian Portuguese by a native speaker of Spanish (Riverplate variety) living in Brazil. We aim to observe the movements and changes of his vowel system, when trying to allocate the mid-low vowels /(sic)/and /epsilon/, not present in the Spanish inventory. The corpus consists of data from longitudinal, spontaneous speech recordings, carried out in a time window of 24 months, with monthly observations between October 2018 and September 2020. The learner (who was proficient in Brazilian Portuguese) participated in weekly sessions of explicit pronunciation instruction on BP for an approximate period of three months. The analyses were carried out with the description and mapping of the acoustic dispersion of the vowel categories, considering the first two formants (F1 and F2), with inferential tests based on Monte Carlo Simulations. This process analysis (cf. Lowie, 2017) made it possible to identify vowel movements and dispersions in the learner's acoustic space, with changes in vowel height and frontness, especially in the mid vowels. These changes are characteristic of developing systems.