[Pronouns] Common Expressions with Other

Mike and I write to each other every week.	Each other and one another indicate a reciprocal relationship.
We write to one another every week.
Please write on every other line.	Every other can give the idea of “alternate.” The meaning in left sentence means:    Write on the first line.    Do not write on the second line.    Write on the third line.    do not write on the fourth line. (Etc.)
--Have you seen Ali recently? --yes. I saw him just the other day.	The other is used in time expressions such as    the other day    the other morning,    the other week. to refer to the recent past. The other day means a few days ago, not long ago.
The ducklings walked in a line behind the mother duck. Then the mother duck slipped into the pond. The ducklings followed her. They slipped into the water one after the other.	one after the other expresses the idea that separate actions occurred very close in time.
They slipped into the water one after another..
No one knows my secret other than Rosa.	Other than is usually used after a negative to mean except.
No one knows my secret except (for) Rosa.
Fruit and vegetables have full of vitamins and minerals. In other words, they are good for you.	In other words is used to explain, usually in simpler or clearer terms, the meaning of the preceding sentence(s).