Is "to" in the following sentence a preposition or an adverb?

Question

"The speaker in "We Never Know How High We Are" believes people can rise to a challenge."

In my opinion, I think it is an adverb. However, I am not entirely certain.

Answer 1

The word "to" is never an adverb. In your sentence, "to" begins the prepositional phrase, "to a challenge." The entire prepositional phrase is an adverb, modifying the verb, "can rise."

For more information, study this site.

http://www.chompchomp.com/terms/preposition.htm