彼は自分のためにだけ働いている。

he; him; his; boyfriend

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

myself; yourself; oneself; himself; herself; I; me; you

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

for; for the sake of; to one's advantage; in favor of; in favour of; on behalf of; because of; as a result of

only; just; merely; simply; no more than; nothing but; alone; as (e.g. as soon as, as much as); worth

to work; to labor; to labour; to function; to operate; to be effective; to work (i.e. ... works); to come into play; to commit (e.g. a crime); to perpetrate; to do; to act; to practise; to practice; to be conjugated