When one should use "å, om å, for å, and til å".
I was just wondering if there is a rule for when one should use one of the four prefixes(?). I have seen them in a few places and when hovering over them, they always give "to" as the translation. I was just wondering in which circumstances one would use one of them over the others.
å is the infinitive marker and the equivalent of to (though "to" can also be a preposition in English, unlike "å" in Norwegian"). In sentences like "å leve er å elske", "to live is to love", the usage is identical in the two languages.
"om å" + infinitive (or "om at" + finite verb) is used for indirect requests - in other words, after verbs like "to ask (to do something)". "I asked you to do it" = "jeg ba deg om å gjøre det". "I asked that it should be done" = "jeg ba om at det skulle gjøres" (in this case, the subject of the subordinate clause is not equal to the Object of the main clause). Note that indirect questions use "om" + finite verb (without the "at". "I asked you if he had done it" = "jeg spurte deg om han hadde gjort det".
"for å" + infinitive (or "for at" + finite verb) is used to state the reason for the action of the main clause, and can be used after any verb. It can be translated into English as "in order to", but it's more usual to just use "to". He did it (in order) to be admired by his friends" = "han gjorde det for å bli beundret av vennene sine". "He did it so that his friends would admire him" = "Han gjorde det for at vennene skulle beundre ham" (in this case, the subject of the subordinate clause is not equal to the subject of the main clause).
"om" and "for" and "til" are also prepositions, which means that you can find "om å" in any setting where you would find "om" + noun. This will often be triggered by a specific verb or adjective. For example, "snakke om livet" = "talk about life" and "snakke om å leve" = "talk about living".
I can't think of any examples of "til å" translating to English as "to". Do you have any?