Here's why:
* Short vowels are typically found in words with a single vowel followed by a consonant (e.g., cat, dog, sun).
* Long vowels can be found in words with a single vowel followed by a silent 'e' (e.g., make, time, fence), or in words with a vowel digraph (e.g., boat, rain, treat).
In the word "fence," the "e" is followed by a silent "e," indicating a long vowel sound.