Remember: 'The' refers to specific things and 'a' refers to non-specific things.
When we use 'the', as in 'the other/others', we refer to the remaining members of a specific group. When we don't use 'the', we refer to members of a broad category.
When we talk about two items in a set, we refer to the first item as 'one' and the second as 'the other (one)'.
One cup is orange, and the other is green.
Sometimes we want to talk about items that are not in a specific set, but belong to some broad category. In this case, we refer to the first item as 'one' and any additional item as 'another' (= short for 'an other'). For instance, to order a beer at a bar, you can say:
Then when you finish that beer, you can ask for one more:
- Another beer, please. (= one more beer)
When we talk about many things in the same set, we refer to the first item as 'one' and the remaining items as 'the others'.
If we want to refer to a first set of items (not just one item), we say 'some' instead of 'one':
- Some students are singing and the other students are dancing.
- → Some students are singing and the others are dancing.
When we talk about large groups of people/things in general and not one specific group, we use 'some' to refer to the first group and '(and) others' to refer to the remaining group.
- Some people like dogs, other people cats.
- → Some people like dogs, others cats.
