To make a word ending with Y plural, use the Change Suffix Ending function. Change the Y to I and add Suffix -ES suffix. The I will most often make the same sound of the Y it replaced.  replaces the Y, as in “puppy” to “puppies”, or “spy” to “spies”. 

This does not work when ending Y is part of a vowel team.

Ending /ēz/, Ending /ēz/. Ending /ēz/. Puppies.
Ending /īz/. Ending /īz/. Ending /īz/. Spies.

When ending Y is followed by Suffix -ES, you may circle the resulting combined Ending -IES. You also have the option of writing the Y below the I that resulted from the Change Suffix Ending function.