Lets see the nominative case in Plural

The Nominative Case - Plural (Subject)

In Russian, in the nominative case, you make a plural by using the letters "и", "ы", "я" or "а".

For masculine nouns:
    If the word ends in a consonant, add “ы”.
    Replace “й” with “и”
    Replace “ь” with “и”

For feminine nouns:

    Replace “а” with “ы” (unless previous consonant is Г, К, Х, Ж, Ч, Ш, Щ then replace with "и" as per                                             the spelling rules.)
    Replace “я” with “и”
    Replace “ь” with “и”
   

For neuter nouns:
    Replace “о” with “а”
    Replace “е” with “я” (don't forget the spelling rules)