彼は裸の背中と腕に玉のような汗をかいていた。

he; him; his; boyfriend

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

naked; nude; bare

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

back (of body)

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

arm; skill; efforts; ability

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

ball; sphere; globe; orb; bead (of sweat, dew, etc.); drop; droplet; ball (in sports); pile (of noodles, etc.); bullet; bulb (i.e. a light bulb); lens (of glasses, etc.); bead (of an abacus); ball (i.e. a testicle); gem; jewel (esp. spherical; sometimes used figuratively); pearl; female entertainer (e.g. a geisha); person (when commenting on their nature); character; item, funds or person used as part of a plot; egg; coin; precious; beautiful; excellent

(usu. at sentence-end) seeming to be; appearing to be; like; similar to; in order to (e.g. meet goal); so that; indicates hope, wish, request or mild command

sweat; perspiration; moisture; condensation

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 scratch; to perspire; to shovel; to paddle