彼は帽子をかぶらずに出かけた。

he; him; his; boyfriend

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

hat; cap

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 put on (one's head); to wear; to have on; to pull over (one's head); to crown (oneself); to be covered with (dust, snow, etc.); to pour (water, etc.) on oneself; to dash on oneself; to ship water; to bear (e.g. someone's debts, faults, etc.); to take (blame); to assume (responsibility); to shoulder (burden); to overlap (e.g. sound or color); to be similar; to be redundant; to be fogged (due to overexposure, etc.); to close; to come to an end; to get a full house; to sell out; to blunder; to bungle; to fail; to be deceived

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

to go out (e.g. on an excursion or outing); to leave; to depart; to start; to set out; to be about to leave; to be just going out