The thought popped into my head when today I tried to use the verb eitra, and simply said Eitra mér... forgetting the fyrir. Now all of a sudden I was thinking, what the hell does fyrir mean in this phrase, whats its purpose, what does it even add.. there are tons and tons and tons of verb constructions in icelandic that seem to have random að við með til á... which are seemingly interchangeable to me. Like... ég hef áhuga á einhverju... if you didn't know the construction is there really any logical way of concluding that á should be used there? Is this something similar to english, could someone give an example of a random preposition used in english that would only make sense to us as I am drawing a blank, or are these prepositions in some respects logical in icelandic? Or are they all just to be memorized and taken as part of the verb.