友達 vs 友人
JLPT N5 vocabulary · what is the difference?
They mean the same thing; the difference is register. 友達 is the everyday spoken word and what you should use by default. 友人 is its formal written counterpart, for essays, self-introductions at work and polite letters. Note that 友達 covers one friend or many with no change of form.
When to use each
友達
ともだち
Use 友達 in conversation and casual writing — this is the default. It is also the word for making friends: 友達になる. It does not mark number, so 友達と行く can be with one friend or with several.
週末に友達と映画を見ました。
しゅうまつにともだちとえいがをみました。
I watched a film with a friend at the weekend.
日本で友達をたくさん作りたいです。
にほんでともだちをたくさんつくりたいです。
I want to make lots of friends in Japan.
友人
ゆうじん
Use 友人 in formal contexts: written Japanese, speeches, business settings, or when speaking politely about someone. It carries a more adult, restrained tone than 友達, but means the same relationship.
大学時代の友人と再会しました。
だいがくじだいのゆうじんとさいかいしました。
I met up again with a friend from my university days.
友人の結婚式に出席いたします。
ゆうじんのけっこんしきにしゅっせきいたします。
I will be attending a friend's wedding.
Sentences where only one works
ねえ、友達になろうよ。
ねえ、ともだちになろうよ。
Hey, let's be friends.
Casual invitation between peers. 友人になろう would sound stiff and distant.
本日は友人を代表してご挨拶いたします。
ほんじつはゆうじんをだいひょうしてごあいさついたします。
Today I offer a few words on behalf of the friends.
A formal speech, so 友人 matches the register.
子どもの友達が遊びに来ました。
こどものともだちがあそびにきました。
My child's friend came over to play.
Children's friendships are normally 友達; 友人 sounds oddly adult here.
友人からいただいた本です。
ゆうじんからいただいたほんです。
It's a book I received from a friend.
The humble いただく sets a polite register that 友人 fits.
Common mistakes
友達たち
友達
友達 already covers the plural, so 友達たち is redundant. You hear it occasionally in casual speech, but it is not standard writing.
昨日、友人と遊びました。
昨日、友達と遊びました。
遊ぶ in the sense of hanging out is casual, and pairing it with the formal 友人 clashes. Match the register across the sentence.
Frequently asked questions
Is 友人 a closer friend than 友達?
No. Neither word says how close the friendship is; the difference is only how formal the wording is. Use 親友 if you mean a close or best friend.
How do I say my friends as a plural?
Just 友達. If you need to make plurality explicit, add a quantity word: 友達が何人か, 友達がたくさん.
Which should I use in a self-introduction?
In a classroom or with peers, 友達. In a written essay or a formal introduction at work, 友人 reads better.