We have been talking about prepositions. A preposition begins a prepositional phrase and shows position.
The word to is a preposition.
Mary is going to the store.
Sarah is walking to school.
I will show my picture to my mom.
Please give this paper to the teacher.
In each sentence, the word to begins a prepositional phrase. That phrase shows position and ends with an object of the preposition.
The word to also works in English as an infinitive. An infinitive is the base form of a verb combined with the word to.
Look at these sentences:
I am going to ride my bike.
I want to hold your hand.
The baseball team is going to practice hitting today.
We are hoping to see the Grand Canyon on our trip.
Can you see the difference in the way the word to is being used?
In the first set of sentences, the preposition sentences, to is at the beginning of a phrase that shows position. There is no action in that prepositional phrase.
In the second set of sentences, the word to is combined with a verb to make an infinitive. The infinitive suggests action.
The word to may be used as a preposition or an infinitive. If the word to is being used to show position, it is a preposition. If the word to is paired with a verb, it is being used as an infinitive.