What does the suffix 'ies' generally relate to?

The suffix 'ies' is commonly associated with forming plural nouns, particularly when the word ends in 'y'. When a word ends in a consonant followed by 'y', the 'y' is usually replaced with 'ies' to indicate that there are multiple instances of that noun. For example, "baby" becomes "babies," and "city" becomes "cities."

This formation is a fundamental aspect of English grammar, specifically related to quantity. Using 'ies' to create plural forms distinguishes it from the other options: states or conditions, comparative adjectives, and scientific or social systems, which do not directly relate to this suffix. Thus, recognizing that 'ies' primarily serves to indicate plurality clarifies its role and function in the language.