私達は彼女のために歌った。

we; us

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

she; her; her; girlfriend; sweetheart

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

to sing; to sing (one's praises in a poem, etc.); to compose a poem; to recite a poem