Adding endings to words that end in -y
When adding endings to words that end with a consonant plus -y, change the final y to i (unless the ending in question, such as -ish, already begins with an i). For example:
pretty: prettier, prettiest
ready: readily
beauty: beautiful
dry: dryish
This rule also applies when adding the -s, -ed, and -ing endings to verbs ending in -y:
defy: defies, defying, defied
apply: applies, applying, applied