This document discusses principles for teaching less commonly taught languages endorsed by STARTALK (Strategic Language Training and Research Training). It emphasizes using the target language for at least 90% of instruction time and making the language, culture and content comprehensible to students. To do so, teachers should paraphrase in simpler terms, use familiar structures and repeat key words and phrases. They should also use gestures, visual aids and meaningful contexts to aid understanding. Formative assessments and integrated performance tasks are recommended to evaluate students' knowledge and language skills. The goal is for students to interpret authentic materials and use the language for daily communication and knowledge acquisition.