as an adverb showing how a sentence is related to what has already been said: Prices have been rising. It is unlikely, however, that this increase will continue.
as an adverb (before an adjective or adverb): However hard he tried, he could not control his feelings. (before ‘much’ or ‘many’): However much they earn, they will never be satisfied. (starting a question): However did you manage to make him change his mind?
as a conjunction (joining two clauses): You can arrange the furniture however you want.However you look at it, it’s an enormous problem.