English UsageComparison guide
Each Other vs. Each Other’s
Use “each other” as the reciprocal expression and “each other’s” before a noun to show reciprocal possession. Cambridge also notes that “each other” is written as two words; plain “each others” is not the possessive form.
Use “each other” for the reciprocal expression and “each other’s” as the possessive determiner before a noun, as in “each other’s work.”
Key details
Base Rolereciprocal expression
Possessive Roleeach other’s before a possessed noun
Termseach other, each other’s
Further guidance
Apostrophe Boundary
The apostrophe marks the possessive form: “each other’s ideas.” Do not form that possessive by writing “each others.”
Spacing Boundary
Write “each other” as two separate words; Cambridge explicitly warns against “eachother.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Each other, one another — Cambridge Grammar (opens in a new tab)Cambridge Grammar · Reciprocal expression each other and possessive determiner each other’s