This study investigates the relative impact of verbal expression and tone of voice when native speakers of English form an impression of non-native speech. Four expressions of inquiry uttered in two tones by non-native speakers were judged by native listeners and analyzed using an ordinal Probit model. Plain expressions received lower scores than polite expressions in both tones, suggesting that appropriate expression is more important than tone of voice. It was found that while a friendly tone can enhance listeners' impression on speakers, particularly when the expression is plain, the impact of tone of voice is less evident when appropriate expressions are used. The study revealed no statistically significant gender differences. On the basis of the study, we offer a pedagogical suggestion that beginners need some instruction to guide their choice of textbook expressions for an effective real-world interaction.