No, "can" is a modal verb used to indicate possibility or ability in a sentence. It is not a preposition.
The pronoun 'us' is the first person, plural, objective; a word that takes the place of a noun for the speaker and one or more others as the object of a verb or apreposition. The corresponding first person, plural, subjective pronoun is 'we'.Example: John and I ordered the special. We were told that they were out so they made something special for us.
No, a prepositional phrase is a group of words introduced by a preposition, a word thatshows the relationship between the noun or a pronoun follows and another word in a sentence.Aprepositionis not a word for an action; apreposition is a word thatdesignates the time, place, or reason relationshipbetweennouns or pronouns. Examples:time: We can get the bus after the movie.place: The man on the corner is waiting for a bus.reason: The man on the corner is waiting for a bus.