The OP compared Russian to Mandarin by counting the number of forms words take in Russian (10-20) and in Mandarin (one). You objected, saying that Russian only

The OP compared Russian to Mandarin by counting the number of forms words take in Russian (10-20) and in Mandarin (one). You objected, saying that Russian only has "5 declinations" and so it could not possibly be that many forms. I corrected you pointing at the many forms different parts of speech take in Russian. Being a native speaker I could not possibly judge how hard or easy is it to learn Russian so I have not made such a judgment. For what I know the OP is not lying and finds it difficult to memorize different forms for almost every single word.