Question

Can anybody explain to me when to use another and when to use other?

Really confusing!

For example, in the followng sentence, which one is right?

If I saw my boyfriend with another girl(or other girl or other girls why?), I would break up with him.

Answer 1

You know the difference between the and a(n).

The difference between the other and another in the singular is like that:

The other person - another person

In the plural you always use other.

So, applying that to your examples:

If I saw my boyfriend with another girl. - a different girl (not me)

If I saw my boyfriend with the other girl - that particular different girl (not me)

If I saw my boyfriend with other girls - this would probably mean a series of different individual other girls, on different occasions.

If I saw my boyfriend with the other girls - a different group of girls (not the girls we have already specified).

Answer 2

I rely on a Collins concise handbook for writers. Mine devotes 1 1/2 pages to the problem of other and another. Some guidelines there are helpful; viz., Another means "one more" in addition to what else might be mentioned. Other means "several more" than what is mentioned. / When used as an adjective another is used with singular countable nouns such as chance. Other precedes plural countable nouns such as houses and noncounable nouns such as information. Exceptions to those rules exist and would best be determined from a grammar manual or handbook.

In your sentence one other girl, singular, is countable and another is the word that you want.

Answer 3