Questions & Answers about Þetta eru sex vikur.
Why do we use Þetta (which usually means 'this') with the plural verb eru?
How is the plural word vikur formed from the singular?
Vikur is the plural of vika (week). For most feminine nouns that end in -a in the singular, you drop the -a and add -ur to make them plural in the nominative case.
What does it mean that vikur is a 'bare' noun in this sentence?
A 'bare' noun simply means it does not have the definite article ('the') attached to the end of it. It just means 'weeks'. If we wanted to say 'the weeks', we would add the plural article to make it vikurnar.
Does the number sex (six) change to match the noun vikur?
No, it stays exactly the same. In Icelandic, only the numbers one through four change their forms to match the gender of the noun they are counting. Numbers from five and up do not change their spelling in the nominative case.