Questions & Answers about Við vorum heima út af óveðrinu.
Why does the word for storm end in -inu here?
The preposition út af (because of) always forces the noun that follows it into the dative case. The base word is the neuter noun óveður (storm). In the dative case with the definite article attached (the storm), it becomes óveðrinu. Notice how the second u in óveður drops out when the ending is added!
Doesn't út af literally mean out of or off?
Literally, yes! You will see it used for physical movement, like driving off a road. However, as an idiom, út af is the standard, everyday way to say because of or due to when explaining the cause of something.
Why use heima instead of heim?
Heima means at home (a stationary location), whereas heim means homewards (indicating movement). Since the sentence says we were at home and there is no travel happening, you must use the static word heima.