1. In 'run fast', the adverb 'fast' is a postmodifier. 在run fast中，副词fast是后置修饰词。
2. In 'speak quietly', the adverb 'quietly' is a modifier. 在speak quietly中，副词quietly是修饰语。
3. In 'walk slowly', the adverb 'slowly' modifies the verb 'walk'. 在walk slowly中，副词slowly修饰动词walk。
4. Above (adverb) can indicate something written earlier in a book or other documents. 作为副词的 above 可指在书或文件前面写的东西。
5. A phrasal verb refers to a verb combined with an adverb or a preposition, or sometimes both, to give a new meaning. 短语动词指的是动词与副词或介词，或者有时两者结合，赋予新的意义。
