Hi!
Maybe this would help you.
Ja må han leva, ja må han leva,
ja må han leva ut i hundrade år.
Javisst ska han leva, javisst ska
han leva, javisst ska han leva ut
i hundrade år!
This song wouldn't make much sense in
English I think, but it's still a happy birthday
song. :P
Best wishes,
Saïd.