在walk slowly中，副词slowly修饰动词walk。

In 'walk slowly', the adverb 'slowly' modifies the verb 'walk'.

《牛津词典》

副词通常用来修饰动词。

Adverbs are always used to qualify verbs.

youdao

形容词修饰名词，副词修饰动词。

Adjectives qualify nouns white adverbs qualify verbs.

youdao

This is a strategy called double syntax, the notion that "in the Beginning" can modify one verb or the other.

这种手法叫做双关句，也就是,“太初“可同时修饰两个动词。

耶鲁公开课 - 弥尔顿课程节选

In the Beginning" can modify the verb "taught" as easily as it can the verb "rose." It can either verb assume, just as Milton's angels can "either Sex assume."

最初“还可修饰动词“宣讲“,也可修饰动词“生出“，它可修饰任意一个动词，正如弥尔顿笔下的天使可以“化男作女“

耶鲁公开课 - 弥尔顿课程节选