"아버지가 딸하고 노래하고 있어요."
Translation:The father is singing with his daughter.
-하고, -와, -과, -랑, and -이랑 are commitative markers in constructions like these. In English, the preposition with is used.
Mods. ..please allow sentences with or without 'a' or 'the'.... it's impossible to guess which (if any) you want! !!
I explained it above. It only means and between nouns. After a subject is declared, the attachment of a 하고 marker indicates that the subject is doing something with the marked item.
Your sentence is different: 아버지하고 딸이 노래하고 있어요.
This sentence is literally:
Father(가) daughter with singing.
Translates to "The father is singing with the daughter."