Here's why:
* The "u" in "ugly" is pronounced like the "u" in "cup" or "sun". This is a short vowel sound, often represented by the letter "u" in the International Phonetic Alphabet (IPA).
* Long vowel sounds are typically associated with a vowel sound that is pronounced like the vowel's name. For example, the "a" in "cake" is a long vowel sound.
Therefore, the vowel sound in "ugly" is a short vowel sound.