Genitive

When a noun refers to a definite place:

• En tas a nef ym gylwyr
  An Tas a Nev y'm gelwir
  The Father of Heaven I am called (OM1)

• Arloth dev an nef an tas
  Arlodh Duw a'n Nev, an Tas
  Lord, God of heaven, the Father (OM105)

• ythyn an nef han bestes
  ydhyn an nev ha'n bestes
  The birds of heaven, and the beasts (OM118)

When a noun refers to a concept:

• yw pren a skeyens hynwys
  yw prenn a skians henwys
  It is named the tree of knowledge (OM80)

• frut an wethen a skyans
  Frut a'n wedhen a skians
  The fruit of the tree of knowledge (OM167)