Here is how the Nominative Plural is formed.
TYPE | ending | Example |
---|---|---|
-а/-я -nouns | ы/и | ма́мы, зе́мли |
-ь -nouns, feminine | и | крова́ти |
most consonant-ending masculines | ы/и | столы́, ма́льчики |
-о/-е -nouns | а/я | о́кна, моря́ |
some consonant-ending masculines | а/я | доктора́, глаза́ |
(so, the plural «я́блоки» is actually an uncommon way of doing it)
There are some irregular plurals too.
Or maybe not. Sometimes Russian forces your choice of vowel to spell or pronounce after a certain letter.
The 7-letter rule: Whenever you make any form of a word, and you need to write И or Ы, check this:
These are velars ("back" consonants) and hushes. For hushes, it is merely a spelling convention, owing to their former "soft" status. For velars, it is true to their pronunciation — i.e., these consonants always use the palatalized И where another consonant would use Ы:
Of these seven consonants, «К» should be your main concern for now. A lot of nouns have it as a suffix or a part of their suffix, forcing you to remember this rule.
The 8-letter rule: Whenever you make any form of a word, and you need to write А, У or Я, Ю after a consonant, follow the rule: