日本では二十歳で成年になる

N3 日本 nippon Japan N5 では dewa then, well, in that case N5 二十歳 hatachi twenty years old N3 成年 seinen majority, adult age N5 なる naru become, turn into, happen

N5 日 nichi, jitsu / hi, -bi, -ka day, sun, Japan N5 本 hon / moto book, present, main N5 二 ni, ji / futa, futa.tsu, futatabi two, two radical (no. 7), deux N5 十 juu, jitsu, jutsu / too, to, so ten, dix, diez N3 歳 sai, sei / toshi, tose, yowai year-end, age, occasion N3 成 sei, jou / na.ru, na.su, -na.su turn into, become, get N5 年 nen / toshi year, counter for years, année

N5 〜に ni Indicates destination, target, arrival point, specific time, or person receiving an action N5 〜で de Indicates where an action happens, means used, tool, cause, or material depending on context N5 〜は wa Marks the topic of the sentence, indicates what the sentence is about, can contrast with another element, organizes main information