警察が事件の捜査を進めた

N4 警察 keisatsu police, police station N3 事件 jiken incident, case, event N3 捜査 sousa search (esp. in criminal investigations, investigation)

N3 警 kei / imashi.meru admonish, commandment, réprimander N3 察 satsu guess, presume, surmise N4 事 ji, zu / koto, tsuka.u, tsuka.eru matter, thing, fact N3 件 ken / kudan affair, case, matter N2 捜 sou, shu, shuu / saga.su search, look for, locate N2 査 sa investigate, investigation, investigar N3 進 shin / susu.mu, susu.meru advance, proceed, progress

N5 〜が ga Marks the grammatical subject, highlights new information, can also show slight contrast in some sentences N5 〜を o Marks the direct object of an action, appears before the verb, shows what receives the action N5 〜の no Indicates possession, relation between nouns, nominal explanation, or turns a verb into a noun phrase