The man of most woes, however, is a hackney-coachman.
Opus, need, and usus, need, require an ablative case, as
Didoni marito opus erat;
Dido had need of a husband.
Æneæ cœnâ usus erat;
Æneas had need of a dinner.
But opus appears to be sometimes placed like an adjective for necessarius, necessary, as
Regi Anthropophagorum coquus opus est:
The King of the Cannibal Islands wants a cook.