He put his hand on his heart.
Kare wa mune ni te o ateta.
he; him; his; boyfriend
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
chest; breast; breasts; bosom; bust; heart; lungs; stomach; heart; mind; feelings
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
hand; arm; forepaw; foreleg; handle; hand; worker; help; trouble; care; effort; means; way; trick; move; technique; workmanship; hand; handwriting; kind; type; sort; one's hands; one's possession; ability to cope; hand (of cards); direction; move (in go, shogi, etc.)
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 hit; to expose; to apply (e.g. patch); to put on; to put against; to hold on; to hold against; to allot; to call on someone (e.g. in class); to guess (an answer); to make a hit (e.g. in a lottery)