1. 'Other' is an adjective. 'Another' is simply a combination of 'an + other', used for singular countable nouns. If you think of 'another' as two separate word, the article 'an' and the adjective 'other', then you'll understand better how to use it. another person other people another day other days You also use 'other' with singular countable nouns when 'an' is replaced with a possessive/demonstrative/other determiner; my other jacket that other book 2. 'Others' is a pronoun used to refer to 'other people' , 'other things' etc. I don't want to wear those shoes, I want to wear the others. I'm reading this book again because I haven't brought any others. Some people agree with these ideas, others don't.

This may help: http://www.grammar.cl/english/another-other-others.htm