Page 185 - Practical English Usage 3ed - Michael Swan, Oxford

170 each and every: the difference
1 each with two or more; every with three or more
Each and every are both normally used with singular nouns. Each can be used to talk about two or more people or things; every is normally used to talk about three or more.
The business makes less money each/every year. (NOT •• •-eachletJery years.) She had a child holding on to each hand. (NOT ••• etJery htmti;)
For expressions like every two years, every tllree steps, see 532.8.
2 meaning
Each and every can often be used without much difference of meaning. You look more beautiful each/every time I see you.
But we prefer each when we are thinking of people or things separately, one at a time. And every is more common when we are thinking of people or things together, in a group. (Every is closer to all.) So we are more likely to say:
Each person in turn went to see the doctor. but
Every patient came from the same small village.
3 structures
We do not use each with words and expressions like almost, practically, nearly or without exception, which stress the idea of a whole group.
She's lost nearly everyfriend she had. (NOT ••• ftetlrly etleh friertd ...J Each can be used in some structures where every is impossible.
They each said what they thought. (BUT NOT They etJerY ...)
Each ofthem spokefor five minutes. (BUT NOT EtJery Bfthem ...)
For more details, see 169 (each) and 193 (ellery).
171 each other and one another
1 no difference
Each other and one another mean the same.
Ann and I write to each other I one arwther every week.
Each other is more common than one another, especially in an informal style.
2 not used as subject
Each other and one another are not normally used as subjects (though this occasionally happens in subordinate clauses in very informal speech).
They each listened carefully to what the other said. (NOT USUALLY They listened carefully to what each other said.)
3 each other's / one another's Both expressions have possessive forms.
They'll sit for hours looking into each other's I one arwther's eyes.
each other and one another 171
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