Here's why:
* Prepositions show the relationship between a noun or pronoun and another word in the sentence. They often describe location, time, or direction.
* In this sentence, "to" is part of an infinitive phrase ("to a preposition"). Infinitive phrases act as nouns, adjectives, or adverbs.
* "To" is the infinitive marker, signaling the beginning of the infinitive.
Example:
* "He went to the store." (Here, "to" is a preposition showing direction.)
* "I want to go to the store." (Here, "to go" is an infinitive phrase acting as the object of the verb "want".)