Japanese Family Words: How to Refer to Your Family vs Others'

17 June 2026

🎯 Want to actually speak Japanese, not just read about it? Practise with a friendly tutor for about the price of a coffee — try a lesson on italki → Affiliate link — supports Wakoku at no extra cost to you.

If you’ve ever learned that “mother” is haha (母) and then heard a Japanese person call out okāsan (お母さん) to their mum, you’ve bumped into one of the most useful quirks of the language. Japanese has two sets of family words: a humble set for your own family when you talk about them to outsiders, and a polite set for other people’s families — which you also use when speaking to your own relatives directly.

It sounds fiddly, but the logic is beautifully consistent. Once you see the pattern, a whole table of vocabulary clicks into place. This guide walks you through every common family term, the uchi/soto thinking behind the split, and exactly when to use which word.

The core idea: uchi (内) vs soto (外)

Japanese constantly divides the world into uchi (内, “inside” — your in-group) and soto (外, “outside” — everyone else). When you describe your own family to someone outside the group, you stay humble and plain. When you talk about someone else’s family — or address your own elders to their face — you use the respectful form, usually wrapped in the honorific お~さん (o-…-san).

So there are two questions to ask before choosing a word:

1. Whose family is it — mine or someone else’s?
2. Am I talking about them, or to them?

Your own family, talked about to an outsider, gets the plain humble word. Everyone else — and direct address — gets the polite word.

The master table of family words

Here are the everyday terms. The middle column is the humble form (your family, talked about to others); the right column is the polite form (others’ family, or addressing your own).

A few words don’t really split this way and stay the same regardless: いとこ itoko (cousin), 甥 oi (nephew), 姪 mei (niece), 孫 mago (grandchild), and 兄弟 kyōdai (siblings).

Older vs younger matters

Notice that Japanese doesn’t have a single word for “brother” or “sister.” You must specify older or younger:

• 兄 ani / お兄さん onīsan — older brother
• 弟 otōto — younger brother
• 姉 ane / お姉さん onēsan — older sister
• 妹 imōto — younger sister

This reflects how much Japanese culture cares about seniority. The general word 兄弟 kyōdai covers “siblings” collectively, and you’ll sometimes see it written 兄妹 or 姉弟 to show the mix of genders, though kyōdai is the safe spoken default.

The おじさん / おじいさん trap

Two pairs catch almost every learner. The only difference is a long vowel — but it changes the meaning entirely:

Stretch that vowel and you age someone by a generation. Calling a woman in her forties obāsan instead of obasan is a classic — and not very welcome — mistake. When in doubt, hold the long vowel clearly for grandparents and keep it short for aunts and uncles.

There’s also a writing nuance for uncle and aunt: 伯父 / 伯母 are used for a parent’s older sibling, while 叔父 / 叔母 are used for a younger one. Both pairs are read oji and oba, so the distinction only shows up in writing.

Talking about your family vs to them

This is where most learners slip. Inside the home, you address your own elders with the polite forms — you call your mum お母さん okāsan, your dad お父さん otōsan, your big sister お姉さん onēsan. That’s normal and warm.

But the moment you describe them to someone outside the family, you switch to the humble form:

• To a coworker: 母は医者です。 → Haha wa isha desu. “My mother is a doctor.”
• Asking about their family: お母さんはお元気ですか。 → Okāsan wa o-genki desu ka? “How is your mother?”

So you say haha about your own mum to an outsider, but okāsan when you talk to her or about someone else’s mum. If you’d like a refresher on the お~さん honorific that powers all of this, our guide to Japanese honorifics breaks down -san, -chan, -kun and more.

One more habit worth copying: younger siblings are usually called by name, not by otōto or imōto. You’d say “Yuki!” rather than “younger sister!” The age-rank words mostly come out when you’re describing relationships to others.

Quick example dialogues

Introducing your family to a friend (humble forms):

私の家族は四人です。父と母と姉と私です。 Watashi no kazoku wa yonin desu. Chichi to haha to ane to watashi desu. “My family has four people: my father, mother, older sister, and me.”

Asking a friend about their family (polite forms):

ご家族は何人ですか。お兄さんはいますか。 Gokazoku wa nannin desu ka? Onīsan wa imasu ka? “How many people are in your family? Do you have an older brother?”

Family vocabulary like this shows up constantly on the JLPT N5, so it’s worth drilling early — you can test your JLPT level to see where you stand. For a closer look at one of these terms, our post on how to say sister in Japanese digs into ane, imōto, and onēsan in more detail.

How to actually remember this

A trick that works well: memorise the family words in pairs, not singly. Learn 父 chichi and お父さん otōsan together, 母 haha and お母さん okāsan together. Your brain stores them as a “humble / polite” unit, and the switch becomes automatic.

Then attach one rule to the whole set: plain word = my family, to outsiders; o-…-san word = your family, or speaking to mine. That single sentence covers almost every case in the table above.

The takeaway

Japanese family words aren’t really two random lists to memorise — they’re one system seen from two angles. Decide whose family you mean and whether you’re talking to them or about them, and the right word falls out every time. Start with the humble/polite pairs for the people closest to you (parents and siblings), use them in real sentences, and the rest of the family tree will follow naturally.