B1–B2

Each Other — Mutual and Reciprocal Actions — English Grammar Exercises

One or ones? Another or the other? Other or others? 60 exercises on substitution pronouns and the most confused words in English at B1–B2.

Each Other: Expressing Mutual and Reciprocal Actions

Each other is a reciprocal pronoun expressing that two (or more) people perform the same action on one another simultaneously: Tom helps Lisa and Lisa helps Tom. It differs from reflexive pronouns (themselves, ourselves), which mean each person performs the action on themselves. Research on learner English shows that reflexive-for-reciprocal substitution — 'They looked at themselves' meaning they looked at each other — is a common B1 error, particularly for speakers whose L1 uses a single form for both reflexive and reciprocal. A second frequent error is the non-existent form 'each others' (plural): 'each other' is invariable and never takes -s, though the possessive is 'each other's' (apostrophe before the s).

Each Other — Mutual Action

Tom and Lisa help each other with homework. (A helps B; B helps A)
We haven't seen each other since the wedding.
My parents call each other every day when they're apart.

Each Other's — Possessive

The twins always finish each other's sentences. (apostrophe before -s)
They borrowed each other's notes before the exam.

Each Other vs Themselves/Ourselves

They looked at each other. (A looked at B; B looked at A — mutual)
They looked at themselves. (each person looked in a mirror — reflexive)

Common Mistakes

✗ Tom and Sara congratulated themselves after winning. → ✓ each other. (they congratulated one another)
✗ We email one other every week. → ✓ each other. ('one other' is not a valid form)
✗ The teachers supported each others during the difficult period. → ✓ each other. (no plural -s on 'each other')

Frequently Asked Questions

What is the difference between 'another' and 'the other'?

'Another' means one more of an open set, or a different one: 'Can I have another cup of tea?' — there are many cups available. 'The other' refers to the remaining one of a closed, known set — typically a pair: 'I have two sisters. One lives in London; the other lives in Paris.' The key test: if the total number is fixed and you are pointing to the remaining item, use 'the other'. If you are adding one more from an unlimited supply, use 'another'.

When do you use 'one' vs 'ones' as a pronoun?

'One' replaces a singular countable noun to avoid repetition: 'I don't like this shirt — can I try the blue one?' (= the blue shirt). 'Ones' replaces a plural countable noun: 'I don't like these shoes — have you got cheaper ones?' (= cheaper shoes). Neither 'one' nor 'ones' can replace an uncountable noun — you cannot say 'I need water, have you got one?'

What is the difference between 'others' and 'the others'?

'Others' (without 'the') refers to other people or things in general — the group is open and unspecified: 'Some people prefer tea; others prefer coffee.' 'The others' (with 'the') refers to the remaining members of a specific, identifiable group: 'Three students passed. The others all failed.' The rule mirrors the general principle of the definite article: 'the' is used when both speaker and listener know exactly which ones are meant.

Can 'another' be used before a plural noun?

In standard use, 'another' is always singular — it cannot precede a plural noun directly: say 'other colours', not 'another colours'. There are two apparent exceptions: 'another few minutes' and 'another couple of days', where 'another' functions as a determiner for the entire noun phrase rather than the noun alone. Outside these fixed phrases, use 'other' before plural nouns.