Source: Czerwionka, L., & Cuza, A. (2017). Second language acquisition of Spanish service industry requests in an immersion context. Hispania, 100(2), 239-260. 

The study focuses on Spanish service industry requests in the context of food and drink for English-speaking learners of Spanish and examines their development of requests throughout a six-week study abroad program in Spain. The study compared the difference between native speakers of Spanish and non-native speaking learners. Results showed pragmatic acquisition over the program with a change in the learners' requests and an increase in appropriateness of the requests over time.