This document presents a study on the syntactic and semantic-pragmatic features of yes-no questions in English and có-không questions in Vietnamese. The study analyzes yes-no questions in films and aims to help learners use them effectively in different contexts. It finds that while the structures of positive yes-no questions are similar, negatives differ between languages. The study also notes differences in how the languages use questions to make requests, commands, and express attitudes. It concludes with implications for teaching English learners and suggestions for further research.