会う vs 合う
JLPT N5 vocabulary · what is the difference?
会う is meeting a person — the person is marked with に (友達に会う). 合う is two things matching, fitting or agreeing — the thing that fits is marked with が (サイズが合う). They sound identical, so the particle and the subject tell you which one is meant.
When to use each
会う
あう
Use 会う when one person meets another. The person you meet takes に (or と for a mutual meeting), and the subject is a person.
明日、友達に会います。
あした、ともだちにあいます。
I'm meeting my friend tomorrow.
駅で先生に会いました。
えきでせんせいにあいました。
I ran into my teacher at the station.
合う
あう
Use 合う when something fits, matches, suits or is correct — clothes, sizes, times, answers, tastes. The thing that fits is the subject (が), and what it fits takes に.
この靴は私の足に合います。
このくつはわたしのあしにあいます。
These shoes fit my feet.
答えが合っていますか。
こたえがあっていますか。
Is the answer right?
Sentences where only one works
駅で友達に会いました。
えきでともだちにあいました。
I met my friend at the station.
A person is the goal of the meeting, marked with に — only 会う works. 合う would be nonsense here.
この服は私に合いません。
このふくはわたしにあいません。
These clothes don't suit me.
The subject is 服, not a person doing the meeting, so it must be 合う. Writing 会いません here says the clothes failed to meet you.
田中さんとは話が合います。
たなかさんとははなしがあいます。
Tanaka and I are on the same wavelength.
A person appears in the sentence, but the subject is 話 — it is the conversation that matches, so 合う. This is the pattern that trips learners up.
時計が合っていませんね。
とけいがあっていませんね。
That clock isn't showing the right time.
Agreeing with the correct time is the matching sense, so 合う.
Common mistakes
明日、友達に合います。
明日、友達に会います。
Writing 合う for meeting someone is the most common slip, because the IME offers both. To a native reader 友達に合う reads like "I suit my friend" — odd enough to stop them mid-sentence.
この靴は私に会いません。
この靴は私に合いません。
The reverse error. Shoes cannot meet you; this has to be 合う.
Frequently asked questions
Can I use 合う for meeting a person?
Not on its own. The only place 合う touches meeting is inside compounds like 話し合う (to talk something over) or 落ち合う (to rendezvous), where the sense is people coming together mutually. For plain "I meet someone", it is always 会う.
They sound the same — how do I tell them apart when listening?
By the particle and the subject. If a person is marked with に or と and the subject is a person, it's 会う. If the subject is a thing — サイズ、時間、答え、気、話 — it's 合う.
Is 会う ever written in kana?
Yes, あう in kana is common in casual writing, and some writers use 逢う for a romantic or long-awaited meeting. 逢う is not a JLPT kanji; you only need to recognise it.