How about called on the boy?
When should one use "kalde på" and when "kalde efter"? Should "kalde til" ever be used?
Kalde på - you want him to come over
Kalde efter - you're looking for him
"Kalde til" is only used in certain constructions, like "kalde til orden" - "call to order", when you want to have someone put something into a certain state.
Why not ringet? We used that for a previous sentence and it was fine.