自分(じぶん)

自分(じぶん) is a reflexive pronoun meaning "oneself." Unlike English, it is not limited to the speaker — it refers back to the subject of the sentence, whoever that may be.

COMMON PATTERNS:

• 自分(じぶん)で: by oneself (emphasizes doing it independently)
• 自分(じぶん)の: one's own (自分(じぶん)の部屋(へや) = one's own room)
• 自分(じぶん)自身(じしん): oneself (emphatic)
• 自分(じぶん)のことは自分(じぶん)でする: to do one's own things by oneself

FLEXIBLE REFERENCE:

自分(じぶん) refers to whoever is the subject:

• 私(わたし)は自分(じぶん)で作(つく)った (I made it myself)
• 彼(かれ)は自分(じぶん)の間違(まちが)いに気(き)づいた (He noticed his own mistake)

AS FIRST-PERSON PRONOUN:
In casual male speech (especially military, sports contexts), 自分(じぶん) is sometimes used to mean "I/me" directly: 自分(じぶん)はそう思(おも)います (I think so).