Icelandic nouns have four cases. Finding the correct form of the word is called declension. This is a simple declension table for the word lamb:
1st caselamb
2nd caselamb
3rd caselambi
4th caselambs
Nobody actually remembers this table by heart, instead people construct some sentence where only a particular case can fit, and see what their own sense of the language tells them.
The helper sentences you use for this are:
  • hér er = here is. This sentence will always need a word in the first case.
  • um = about. This word will always need a word in the second case.
  • frá = from. This word will always need a word in the third case.
  • til = to. This word will always need a word in the fourth case.
And since the declension table is always shown in the same order, we fill in our table like so:
1st casehér er lamb
2nd caseum lamb
3rd casefrá lambi
4th casetil lambs
When declining words that are plural, you switch “hér er” out with “hér eru”:
1st casehér eru lömb
2nd caseum lömb
3rd casefrá lömbum
4th casetil lamba

See also