اشْتَرَيْتُ الْعَبْدَ كُلَّهُ — I purchased the entire slave.
اشْتَرَيْتُ: past verb; -tu is subject.
الْعَبْدَ: accusative direct object.
كُلَّهُ: accusative semantic emphasis, with -hu as mudāf ilayh.
Kullahu follows the accusative object; it is not a second object.