whats the difference between; moya, moi and moë? Moya is singular while moi is pluralis?
Мой goes with masculine nouns and adjectives.
Моя goes with feminine nouns and adjectives.
моё is neuter and мои is plural.
Here is the link that I got this info from:
Is it a rule that words ending in 'o' are all neuter ?
Yes. Also words ending in "-е" and "-ё".
s there a rule for identifying masculine and feminine words by their endings?
Feminine nouns end with "-я" or "-а" (except the words describing a male person by default, like "папа" ("dad"), "мужчина" ("man"), "дядя" ("uncle") etc,). Masculine nouns end with a consonant (including "-й"). Nouns ending with "-ь" can be either masculine or feminine. That one is pretty random, unfortunately. While there are some patterns, for the most pert you just have to remember the gender of a given word.
There are exceptions to that, but that's the general idea.