1. The "y" is preceded by a consonant:
- For example: baby -> babies, city -> cities, story -> stories
2. The word is singular and you are making it plural:
- This is the main reason for the change.
Exceptions:
* Words ending in "y" preceded by a vowel:
- They form the plural by adding an "s" instead of "ies".
- For example: boy -> boys, toy -> toys, monkey -> monkeys
* Proper nouns:
- They follow their own rules for pluralization.
- For example: Henry -> Henrys, Mary -> Marys
Let me know if you'd like more examples or have any other questions!