föstudag

In a sentence

• Við förum í bíó á föstudaginn.

  We are going to the cinema on Friday.

  The word 'föstudaginn' in this sentence refers to a direct mention of Friday as a specific day when an action will take place. Its suffix indicates the definite form.

• Ég elska föstudaga því þá hefst helgin.

  I love Fridays because the weekend begins then.

  Here, 'föstudaga' is in plural form to generalize about all Fridays, commonly expressed when talking about routines or recurring events.

• Læturðu þig dreyma um ný verkefni á föstudögum?

  Do you dream about new projects on Fridays?

  In this context, 'föstudögum' is in the dative plural form, used to indicate an ongoing or habitual activity occurring on Fridays.