What function does "back" serve in the sentence "A guide directed us back to our hotel."?

In the sentence "A guide directed us back to our hotel," the word "back" serves as an adverb. It modifies the verb "directed" by specifying the direction in which the guide is leading the group. Adverbs often provide additional information about the action of the verb, answering questions like how, when, where, or to what extent. Here, "back" indicates the movement toward a previous location — the hotel, which clarifies the action of being directed.

In this context, "back" does not function as a noun or a verb, which would imply it serves as a subject, object, or action word. Additionally, it is not functioning as an adjective since it does not describe or modify a noun directly. Instead, it provides clarity regarding the action and its direction, solidifying its role as an adverb.