彼、危険を察知してすぐに退いた

N5 彼 kare he N4 危険 kiken danger, risk, dangerous N5 すぐに sugu ni immediately, soon, right away

N3 彼 hi / kare, kano, ka.no he, that, the N3 危 ki / abu.nai, aya.ui, aya.bumu dangerous, fear, uneasy N3 険 ken / kewa.shii precipitous, inaccessible place, impregnable position N3 察 satsu guess, presume, surmise N4 知 chi / shi.ru, shi.raseru know, wisdom, savoir N3 退 tai / shirizo.ku, shirizo.keru, hi.ku, no.ku, no.keru, do.ku retreat, withdraw, retire

N4 〜し shi Indicates multiple reasons or qualities, connects clauses or adjectives, means besides that, and also N5 〜を o Marks the direct object of an action, appears before the verb, shows what receives the action N5 〜に ni Indicates destination, target, arrival point, specific time, or person receiving an action