used in writing to represent the sound that people make when they disagree with someone

"Sour cream on chilli is gross." - "Nuh-uh. Not true. Not at all." “辣椒上的酸奶油很恶心。” “呃不，不是这样的。一点也不。”

Nuh-uh, it's not happening. 呃不，不可能。