Both Carol and Joshua, speakers of L1 English and L2 Spanish, were recently granted opportunities to learn two of the most common indigenous languages in South America–Kichwa and Guaraní. We lived with Spanish-dominant bilingual families who spoke the target language (L3) we were studying. We both kept learning journals recording our language learning progress. After highlighting the tradition of journal-based studies of language learning, and reviewing the perspectives on interaction in second language acquisition, we first describe the contexts for bilingualism in Ecuador and Paraguay. Second, we present data from our journals to illustrate how each of our language acquisition experiences was shaped not only by that particular bilingual context, but by a confluence of linguistic, pedagogical, socioeconomic, and cultural forces.