"Across from" (American English) and "opposite" (British English) are equivalent prepositions of place. They talk about the location of two people, places or things in relation to each other. The object of the preposition is what is across from/opposite the subject of the sentence: The bank is across from/opposite the post office. We can (but don't have to) say across *what* with "across from": The bank is across the street from the post office. "Across" (as a preposition of movement) describes motion from one side of something to another: He ran across the street. She swam across the river.

All of them mean 'on the other side of '; it could be a street, pathway for pedestrians e g. in a shopping centre, or even a river : 'across the river (from . .), on the opposite side . .' 'The post office is across the street', 'The café is across the park' : 'from' is omitted as it is understood that it is across from where you are or where you will be. 'The post office is across the street from the market’ ; 'The post office is opposite the market.’ : this information applies whether you are at the market or not. 'Opposite’ could mean across the street, or facing towards the other site, and close to it e g across a pathway, square, etc.

no, it works the other direction not "which words are used with 1 across 2 across from and 3 opposite" but it's the words which is used after rules the choice of there three words imagine 1 a baseball cap, 2 a woolen hat and 3 a crown which should wear a king who's goind to a baseball match in winter ?