What part of speech is "down" in "The robbers were driven down the street"?

In the sentence "The robbers were driven down the street," the word "down" functions as an adverb. Adverbs modify verbs, adjectives, or other adverbs by providing additional information about the manner, place, time, or degree of the action. In this case, "down" describes the direction of the action of the verb "driven," indicating where the robbers were driven.

It specifically helps clarify the movement involved, pointing out that they were driven toward a lower position along the street. The term "down" in this context conveys a sense of movement or position relative to another point, which aligns perfectly with adverbial function. This contributes to the overall meaning of the sentence by describing not just what happened, but how and where it happened.