私は三日勉強しました。

N5 私 watashi I N5 三日 mikka three days N5 勉強 benkyou study, learning

N4 私 shi / watakushi, watashi private, I, me N5 三 san, zou / mi, mi.tsu, mitsu.tsu three, trois, tres N5 日 nichi, jitsu / hi, -bi, -ka day, sun, Japan N4 勉 ben / tsuto.meru exertion, endeavour, encourage N4 強 kyou, gou / tsuyo.i, tsuyo.maru, tsuyo.meru, shi.iru, kowa.i strong, fort, fuerte

N5 〜ます masu Used at the end of verbs, polite present or future form, makes the sentence more polite N4 〜し shi Indicates multiple reasons or qualities, connects clauses or adjectives, means besides that, and also N5 〜は wa Marks the topic of the sentence, indicates what the sentence is about, can contrast with another element, organizes main information