United States Department of State Foreign Service officers are usually required to learn a language spoken in the country of their onward diplomatic position. Their primary objective is functional ability to do their jobs using the target language. The Foreign Service Institute (FSI) trains (a) diplomats (e.g., consular affairs, public diplomacy, management, and political or economic officers) and (b) specialists (e.g., diplomatic security, information technology, financial management, and general services) in more than sixty languages. We derived this case study from FSI’s Spanish tradecraft curriculum developed with and for specialist officers, who are Diplomatic Security (DS) agents. About half of all FSI Spanish students are returning students, already experienced at their jobs, needing to learn Spanish for their next onward post. The other half typically are entry-level officers and first-time language learners, who preferably attend FSI’s introductory tradecraft training in English before enrolling in Spanish.