How does the words at two schools function in a sentence?

The phrase "at two schools" functions as a prepositional phrase in a sentence. It modifies a noun or verb by telling us where something is happening or where something is located.

Here's how it works:

* Preposition: "at"

* Object of the preposition: "two schools"

Here are some examples:

* "The students were volunteering at two schools." Here, "at two schools" modifies the verb "volunteering" by telling us where the students were volunteering.

* "There were separate events at two schools." Here, "at two schools" modifies the noun "events" by telling us where the events took place.

It's important to note that the phrase "at two schools" is functioning as an adverbial phrase in both of these examples. This is because it modifies the verb or noun by providing information about the location.