“Each other’s” is used when you refer to the singular possessive form of “each other,” which we’ll touch more on later. “Each others'” is used when you need the plural possessive form of “each other.”

The possessive of each other is each other’s, never each others’.

Use others’ for plural possessive form, such as “The others’ opinions are very important to me.” Other’s acts as the singular possessive form. Each other’s is the correct possessive form of the word each other. One another is an acceptable alternative to each other. It simply means that everyone is involved.

Each other is singular, so the correct possessive is each other's.

The plural possessive of others is others’. If a word already ends in “s” in English, then you put the apostrophe after the “s.” Where does the apostrophe go in others? The answer depends on whether “others” refers to the singular or plural possessive. If you are using each other (singular), then it is “each other’s.”