Translation guide
The English phrase "with each other" expresses mutual or reciprocal action between two or more people or things. In Japanese, this is most commonly expressed using the adverb お互いに (otagai ni) or the noun お互い (otagai) in combination with verbs. However, Japanese often omits this phrase when the context makes the mutual relationship clear, especially in casual speech. Direct translation can sometimes sound unnatural or overly explicit.
They talked with each other.
Natural but slightly formal; often omitted in casual speech.
They talked with each other. (casual)
Using the compound verb 話し合う (hanashiau) is more natural for mutual discussion.
Expressing that two or more parties do something together or reciprocally.
They talked with each other. · We helped each other. · The two ideas conflict with each other.
The most direct and versatile way to express 'with each other'. お互いに (otagai ni) is an adverb meaning 'mutually' or 'each other'. It can be used with many verbs to indicate reciprocal action. It is neutral in formality and widely understood.
We helped each other.
They write letters to each other.
A very common and natural way to express mutual action. The auxiliary verb 合う (au) attaches to the stem of another verb to mean 'do something to each other'. This is often more idiomatic than using お互いに. Note that the resulting compound verb is intransitive if the base verb is intransitive, and transitive if the base verb is transitive.
We often talk with each other.
Let's help each other when in trouble.
In Japanese, the mutual nature of an action is often understood from context, especially with verbs that inherently imply interaction (e.g., 話す, 会う, けんかする). Adding お互いに or 合う can sometimes make the sentence sound overly explicit or redundant. In casual conversation, it's common to simply use the verb without any reciprocal marker.
Only omit when the context clearly indicates mutual action. In formal or written contexts, it's safer to include a marker.
I talked with him yesterday. (implying mutual conversation)
We often fight with each other.
A slightly more formal or written variant of お互いに. The prefix お is dropped. Used in similar ways but can sound more stiff or literary.
The two countries promised to cooperate with each other.
A formal, often technical term meaning 'mutually' or 'reciprocally'. Used in official documents, academic writing, or business contexts. Not common in everyday speech.
The two parties have a relationship that brings benefits to each other.
Expressing that people are together or accompany each other.
They went to the park with each other. · We sat next to each other.
When 'with each other' means 'together', the most natural translation is 一緒に (issho ni). This is the standard way to say people do something together. It does not explicitly mean 'each other' but conveys the same idea in context.
They went to the park with each other.
We sat with each other.
To express 'each other's' (possessive), use お互いの (otagai no). This is useful for phrases like 'with each other's help' or 'next to each other'.
They sat next to each other.
Both express mutual action, but 〜合う is often more natural and integrated into the verb. お互いに can be used with any verb, but may sound slightly more explicit or formal. In many cases, 〜合う is preferred in everyday speech.
help each other (explicit, slightly stiff)
help each other (natural, idiomatic)
English often uses 'with each other' where Japanese would simply use a plural subject and a verb. For example, 'They met with each other' is redundant in Japanese because 会う (au) already implies meeting mutually. Saying お互いに会った is possible but often unnecessary. When in doubt, consider whether the verb itself implies reciprocity.
They looked at each other.
Idiomatic phrase using 見合わせる (miawaseru).
We should respect each other.
The two colors contrast with each other.
For inanimate objects, お互いに is common.
We need each other's help.