What are some words that you change y to I and add es I?

You're describing a specific spelling rule in English, which applies to certain nouns ending in "y" preceded by a consonant. Here's how it works and some examples:

The Rule:

* If a noun ends in "y" preceded by a consonant, change the "y" to "i" and add "es" to form the plural.

Examples:

* baby -> babies

* city -> cities

* fly -> flies

* story -> stories

* berry -> berries

* country -> countries

Exceptions:

* Proper Nouns: Proper nouns (names of people, places, etc.) often have irregular plural forms. For example, "Mary" doesn't become "Maries."

* Words ending in "y" preceded by a vowel: These words simply add "s" to form the plural. For example, "boy" becomes "boys."

Let me know if you'd like more examples!