The Vietnamese phrase "gật gà gật gù" is an example of reduplication, which means it repeats sounds to create a rhythmic effect. In English, it can be understood as a way to describe someone nodding their head repeatedly, often in agreement, acknowledgment, or even drowsiness.
Informal Setting: "Khi cô giáo giảng bài, cả lớp chỉ ngồi gật gà gật gù."
(When the teacher was lecturing, the whole class just sat there nodding along.)
Casual Conversation: "Tôi thấy anh ấy gật gà gật gù khi nghe câu chuyện."
(I saw him nodding off while listening to the story.)