An adverb is used to modify the adjective or verb as an adverbial adjunct, it should be put before them. Verbs or even nouns ending with character "地" and functioning as adverbs remain to be regarded as adjectives. Adverbs can also be used as conveyors of affirmation or negation, such as "不", "没", "没有"， "一定"， "准", "未必", "必然", "必定", "未", "别", "莫", "休", "勿", etc.

e.g. （1）我不是学生。 （2）他没看书。 （3）你一定见过他。 （4）你准见过他。 （5）你未必见过他。 （6）我从未见过他。 （7）你别去了。 （8）莫慌。 （9）请勿在此地乱丢垃圾。