This question involves identifying nouns in Hindi - as to which are masculine and which are feminine. Obviously if the word ends with "a" it is considered masculine, and if the word ends with "i" it is considered feminine (with some exceptions to this rule). However, I am curious as to why certain nouns are considered masculine vs. feminine, where the "a" and the "i" rule do not apply.
Example: Sham (Evening) - feminine, where Din (Day) is masculine.
Are there certain categories that masculine nouns fall under, and others that feminine nouns fall under? Or is there simply no logic to it at all?