Here's why:
* Short vowel sounds are typically represented by a single vowel letter in a word. They often have a quick, closed-mouth sound. Examples include the "a" in "cat," the "e" in "bed," the "i" in "pig," the "o" in "dog," and the "u" in "cup."
* In the word "head," the vowel sound is actually a long "e" sound, similar to the "ea" in "eat" or the "ee" in "see."
Therefore, "head" does not have a short vowel sound.