He traveled around the world.
Kare wa sekai isshū o shita.
he; him; his; boyfriend
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
the world; society; the universe; sphere; circle; world; renowned; world-famous; well-known outside of Japan; realm governed by one Buddha; space
once around; a revolution; a lap; a turn; a round; one full year
indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.
to do; to cause to become; to make (into); to turn (into); to serve as; to act as; to work as; to wear (clothes, a facial expression, etc.); to judge as being; to view as being; to think of as; to treat as; to use as; to decide on; to choose; to be sensed (of a smell, noise, etc.); to be (in a state, condition, etc.); to be worth; to cost; to pass (of time); to elapse; verbalizing suffix (applies to nouns noted in this dictionary with the part of speech "vs"); creates a humble verb (after a noun prefixed with "o" or "go"); to be just about to; to be just starting to; to try to; to attempt to