In English, the word “the” is a seperate word (“the day”), while in Icelandic it is attached to the end of the word (“dagurinn”). It is known as the definite article and its form changes depending on the word’s gender, case, and plurality.
Understanding how to create the various forms of the definite article is easier if we think of it as it’s own seperate word (which it more or less originally was before it merged with the word before it).[a] Icelandic does indeed have a standalone word for “the”, but it does not exist outside of extremely formal and official-sounding language. That is the word hinn.[b] To make “the day” we add the word “hinn” behind it: “dagur hinn”. Remove the “h” and you’re left with the correct form “dagurinn” (the day).
“Hinn” is the form used for the nominative case (the first case) of masculine singular nouns. Taking two more examples:
- Köttur is a masculine noun. To add a definite article to it, we create “köttur + hinn”. Wedon’t care about the “h” and so we’re left with “kötturinn” (the cat).
- Hamborgari is also a masculine noun. To add a definite article to it, we create “hamborgari + hinn”. We don’t care about the “h” and you’re left with “hamborgari + inn”. Here we have a little bit of a problem as now we have two vowels in competition, and we can’t leave them both. The vowel in the noun is much more important than the vowel in the definite article, so we’re left with “hamborgari + nn”. The result is the correct form “hamborgarinn” (the hamburger).