После окончания школы он начал рабо

После окончания школы он начал работать в конторе своего отца

Результаты (английский) 1:

After graduation he began working in his father's Office

Результаты (английский) 2:

After graduation, he began working in the office of his father

Результаты (английский) 3:

After the end of the school he began work in his father's office