роки - plural form of 'рік' in Nominative case
року - singular form of 'рік' in Genitive case
Is there a resource to learn about what a "case" is? We don't have these in English, so i have no idea what anyone is talking about when they throw around these terms.
There is a good summary at the website ukrainiangrammar.com:
Wow. That's confusing. I don't know how I'm going to remember all those cases! The page you linked doesn't explain how to conjugate(?) nouns depending on their case. Is there somewhere to find the rules for this?