This is the 840th most frequent Icelandic word.
manni
The Icelandic word "manni" is the dative singular form of "maður," meaning "man" or "person."
Here "manninum" is in the dative case, referring to the indirect object.
Ég gaf manninum bókina.
I gave the man the book.
Here "maðurinn" is in the nominative case, acting as the subject of the sentence.
Maðurinn er úti.
The man is outside.
Here "manninn" is in the accusative case, acting as the direct object in the sentence.