"He is a child."
Translation:Han er et barn.
There's a lot to unpack here but I'm only still learning too, so I don't know this barned/object stuff sorry :( but I know this:
Et barn-a child Barnet-the child En gutt-a boy Gutten-the boy
I don't think it has to do with nouns being objects, but definite vs indefinite
Hope this is still somewhat helpful :)