Hver dagur er góður.

to be

Breakdown of Hver dagur er góður.

• góður: good
• dagur: the day
• hver: each

Questions & Answers about Hver dagur er góður.

In English hver usually means who or which. How can it mean every here?

Icelandic hver has two main uses:

1. Interrogative / relative: hver = who / which

   • Hver maður kom? – Which man came? / Who came?

2. Quantifier meaning “each / every” (as in your sentence):

   • Hver dagur er góður. – Every day is good.

Which meaning you get depends on context, word order, and punctuation.
With a period and neutral intonation, Hver dagur er góður. naturally means Every day is good.
With a question mark and rising intonation, Hver dagur er góður? would be Which day is good?

Why is it hver dagur and not hver dag?

Because hver dagur is the subject of the sentence, so it has to be in the nominative case.

• dagur = day (nominative singular, masculine)
  
  • Nom: dagur
  • Acc: dag
  • Dat: degi
  • Gen: dags

In Icelandic, the subject of a normal “X is Y” sentence is nominative:

• Dagur er góður. – The day is good.