否定词, translated as 'negative adverbs' in English, are used in Mandarin Chinese to negate or show the negative of an action or condition. There are two main negative words 使用 in Chinese: 不 (bù) and 没 (méi). 不 (bù) is used to express a general negation or denial, while 没 (méi) is primarily used to express the non-existence or absence of something or to negate past actions.