Questions & Answers about Ég kaupi köku og glas af mjólk.
Why is there no a before köku?
Icelandic does not have a separate indefinite article. Indefiniteness is shown by leaving the noun in its base form (here the accusative singular köku), so Ég kaupi köku literally means “I buy (a) cake.”
Why is köku spelled with ö instead of a like kaka?
Because köku is the accusative (and dative) form of kaka (“cake”). In strong feminine nouns the vowel a often changes to ö in oblique cases.
• Nominative sg.: kaka
• Accusative sg.: köku
• Dative sg.: köku
• Genitive sg.: kökunnar
What case is köku and why is that case used here?
It’s in the accusative singular, because kaupa is a transitive verb that takes its direct object in the accusative case.
What does af mean in glas af mjólk, and why is it necessary?