Gender

Nouns come in 3 genders, masculine, feminine and neuter. This alters article, demonstratives and adjectives. There is no way to tell the gender of a noun without simply knowing - it's irregular.

-en can be added to teh end of a noun to make them feminine, with the root vowel being pulled more forward.
e.g: 'man' - person, 'mænen' - female person