合う
Do to Each Other
The suffix 〜合う (V-au) creates a compound verb meaning 'to do something to each other' or 'mutually.' It is used for reciprocal actions like talking, helping, or looking at one another.
How It Works
1. Formation
To form this pattern, take a verb in its ます form, remove the 'masu', and attach 合う（あう）.
- 話す（はなす）→ 話し + 合う = 話し合う (to discuss/talk to each other)
- 助ける（たすける）→ 助け + 合う = 助け合う (to help each other)
2. Conjugation
The resulting compound verb conjugates as a standard Group 1 (U-verb).
3. Usage Nuances
While often translated as 'each other,' it is not limited to just two people. It can describe a group of people interacting, such as a community helping one another. It emphasizes interaction rather than just simultaneous action. For example, 'eating together' is just eating at the same time, but 'sharing food' (分け合う) involves a reciprocal social exchange.
Examples (4)
- 困った時は、お互いに助け合いましょう。
Let's help each other when we are in trouble.
Word by Word: Troubled time when, mutually help-each-other let's.
助け合う (help each other) is used here with お互いに (mutually) to emphasize the reciprocal support.
- 二人は黙って見つめ合っていた。
The two of them were staring at each other in silence.
Word by Word: Two people (topic) silently stare-each-other were.
見つめ合う means to gaze into each other's eyes. The ている form shows the ongoing state.
- 新しいプロジェクトについて話し合った。
We discussed the new project.
Word by Word: New project about talk-each-other-past.
話し合う (talk to each other) is the standard way to say 'discuss' or 'deliberate' in Japanese.
- 私たちは食べ物を分け合いました。
We shared the food among ourselves.
Word by Word: We (topic) food (object) divide-each-other-polite-past.
分け合う (divide/share) shows that the act of dividing the food was a mutual benefit for the group.
Common Mistakes
Using incompatible intransitive verbs.
道で友達と行き合いました。道で友達とすれ違いました。You cannot simply attach 合う to any verb to mean 'each other.' For 'passing each other' on the street, the specific verb すれ違う must be used instead of 'go-each-other'.
Redundant use of the particle と (with).
田中さんと山田さんと話し合いました。田中さんと山田さんが話し合いました。When listing the participants as the subject, use が or は. If you use と, it should be 'Person A (subject) talked with Person B,' not 'Person A with Person B with talked-each-other'.
How It Connects
Learn This First
To use the pattern 合う (to do to each other), learners must first understand how to conjugate verbs into their stem form (pre-masu form). This requires knowledge of Japanese verb groups and the rules for forming the polite 'masu' form.
Related Patterns
- て形Te-form
Compound verbs ending in 〜合う conjugate into the て form like any other Group 1 verb (〜合って).
Level 2 - ているProgressive/resultative
Often used with 〜合う to describe an ongoing mutual action, like 'staring at each other'.
Level 2 - すぎるToo Much
Another common auxiliary verb that attaches to the [Masu-stem] to add a specific meaning (doing too much).
Level 2 - 始めるBegin to
Like 〜合う, this is a compound verb pattern that attaches to the [Masu-stem] to indicate the start of an action.
Level 2
Words in This Pattern
Practice 合う in Bubblegum
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