どちらの端が尖っているかやっと理解できた後、彼は警備の任務につくことができた。
Once he'd worked out which end of the thing was sharp, he was promoted to guard duty.
棒のどっちが尖っているか理解ができたことで、彼は警備役に昇格した。
Once he'd worked out which end of the thing was sharp, he was promoted to guard duty.