彼は興奮を抑える事ができなかった。

he; him; his; boyfriend

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

excitement; stimulation; agitation; arousal

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 pin something down; to hold something down; to hold something back; to stop; to restrain; to curb; to seize; to grasp; to arrest; to gain control of something; to govern; to keep down (e.g. information); to suppress; to catch happening; to determine (important points); to find (proof); to understand

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to be able (in a position) to do; to be up to the task; to be ready; to be completed; to be made; to be built; to be good at; to be permitted (to do); to become intimate; to take up (with somebody); to grow; to be raised; to become pregnant