Phonetic and affective roles of co-speech gesture in L2 pronunciation

Abstract Second-language (L2) instructors often use hand gestures to teach pronunciation, yet empirical benefits vary in size and scope. Focusing on L2 Mandarin tone production, we explored whether physically exaggerating and emotionally emphasizing tone gestures enhanced pronunciation. Participants imitated videos of a native speaker producing tones in three conditions: Speech Alone (S), Speech + ​Gesture (SG), and Speech + ​Gesture +​ Enthusiasm (SGE). In S, the native speaker spoke tones without arm movements or enthusiastic facial expressions. In SG and SGE, exaggerated hand gestures followed tone contours, and in SGE, the speaker also produced enthusiastic facial expressions. While gesture and enthusiastic expressions yielded only modest pronunciation benefits—slightly higher F 0 for Tone 1 and greater Tone 3 lengthening toward native values—self-ratings of motivation, enjoyment, preference, and helpfulness were substantially higher for SG and SGE than S, suggesting that gesture and enthusiastic expressions in L2 may influence affective experience more than correct pronunciation.