"Another" and "other" have different meanings. Both can be used with nouns in singular but "other" must be always used with the definite article "the" - "the other" or a possessive pronoun.
"Another" used with a noun in singular means "one more or different:
Would you like another cup of coffee?
I don't like this bag. Will you show me another bag, please?
"The, my, your,etc other" used with a noun in singular means the second of two people or things:
He raised one arm and then the other.
My other sister is a doctor. (It means that the person has only two sisters.)
"Another" used with a noun in plural means "in addition":
I have read 50 pages and I have to read another 70 pages.
"Other" used with a noun in plural means "additional or different".
Do you have any other questions? or
Do you have another question?
You can't say "Do you have another questions?" I think we use "another" with a noun in plural when we have information about those people or things:
I must answer another 25 questions.