TKG English Learner's Dictionary

each other

each otherpronoun

American /ˌitʃ ˈʌð.ɚ/ British /ˌiːtʃ ˈʌð.ə/
very common

  1. used when each of two or more people or things does something to the other or others

    Each other is used only as an object, after a verb or a preposition, never as a subject: they help each other, not each other help them. The possessive is each other's. The subject must be plural, or two people joined by and.

    Collocations

    phrase know each other, love each other, help each other, look at each other, talk to each other

    Synonyms one another (one another means the same; some writers keep it for more than two people, but most use the two freely)

    Compare themselves (they hurt themselves means each one hurt himself or herself; they hurt each other means each hurt the other); other

Word family

Common mistakes

Each other helped them. They helped each other.
Each other is never a subject.
We often write to us. We often write to each other.
For an action that goes both ways, use each other, not us or ourselves.
each others' ideas each other's ideas
The possessive is each other's, with the apostrophe before the s.

For translators

Meaning across languages Many languages express this meaning with a reflexive or reciprocal verb form or a single particle rather than a pronoun. English needs the two-word pronoun as the object.
Grammar trap Each other is only an object, after a verb or a preposition, and needs a plural subject: they help each other, we wrote to each other. It cannot be a subject. It is not the same as themselves: they blamed themselves means each blamed himself or herself.
Pronunciation trap The stress falls on other; each is weaker. The th of other is the sound of this, not of thin.