Japanese uses different family words depending on whose family you mean: humble/plain terms for your OWN family, and respectful terms for SOMEONE ELSE's family.
Own family: plain terms (父, 母, 兄, 姉) | Others' family: respectful terms (お父さん, お母さん, お兄さん, お姉さん)
父は銀行員です。
Chichi wa ginkouin desu.
My father is a bank employee.
父 (my father — plain/humble form) + は + 銀行員です (is a bank employee)
お父さんはお元気ですか?
Otousan wa ogenki desu ka?
Is your father doing well?
お父さん (your father — respectful form) + は + お元気ですか (is he well?)
母は毎晩ごはんを作ります。
Haha wa maiban gohan o tsukurimasu.
My mother cooks dinner every evening.
母 (my mother — plain/humble form for one's own family) + は + 作ります (makes)
• The rule of face: don't use respectful terms (お母さん, お兄さん) for your own family when speaking to outsiders — use the plain forms (母, 兄) to humbly lower your in-group and show respect. • Siblings: Japanese distinguishes older vs younger: 兄 (older brother) / 姉 (older sister) / 弟 (younger brother) / 妹 (younger sister).
The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones 家族 is tested against.
父/母 are the humble words for your OWN parents (used to outsiders). お父さん/お母さん are respectful — for someone else's parents, or when addressing your own parents directly at home.
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