私には兄弟が三人います。

N5 私 watashi I N5 兄弟 kyoudai siblings, brothers N5 三 san three N5 人 hito person, people N5 います imasu there is / exist (living things)

N4 私 shi / watakushi, watashi private, I, me N4 兄 kei, kyou / ani elder brother, big brother, frère aîné N4 弟 tei, dai, de / otouto younger brother, faithful service to elders, frère cadet N5 三 san, zou / mi, mi.tsu, mitsu.tsu three, trois, tres N5 人 jin, nin / hito, -ri, -to person, être humain, personne

N5 〜ます masu Used at the end of verbs, polite present or future form, makes the sentence more polite N5 〜が ga Marks the grammatical subject, highlights new information, can also show slight contrast in some sentences N5 〜に ni Indicates destination, target, arrival point, specific time, or person receiving an action N5 〜は wa Marks the topic of the sentence, indicates what the sentence is about, can contrast with another element, organizes main information