To is the preposition.
Before is a preposition, so it's grammatically incorrect to use it as the last word in a sentence.
It is an interrogative sentence.
you
last night was munificent
* students * umbrella * Evanston * night
on
The word, "for" is the preposition in your sentence.
A clause used as the object of a preposition is called a noun clause. A noun clause takes the role of a noun. In the sentence, "I do not know anything except what I saw last night. " The preposition is "except" and its object is the noun clause "what I saw last night".
The object of the preposition "to" is "you."
The last word of a prepositional phrase is called the "object of the preposition." It is the noun or pronoun that the preposition relates to the rest of the sentence.
last night
Before is a preposition, so it's grammatically incorrect to use it as the last word in a sentence.
night is a noun last is an adjective
to / forI want to apologize to youI want to apologize for last my behaviour last night
It is an interrogative sentence.
This is an incomplete sentence, there is no subject. Did I have too much to drink last night? Did you have too much to drink last night? Did they have too much to drink last night? How much was too much to drink last night? Was the wine too much to drink last night? The subjects to these sentences are I, you, they, how much, and wine.
The sentence is better if the "for" is used in place of "since".