Here's why:
* Short vowels have a short, quick sound. They are typically found in words with a single vowel followed by a consonant. Examples include "cat," "dog," "run."
* The vowel in "walk" is a long vowel sound. The "a" in "walk" has the same sound as the "a" in "father" or "car." This long vowel sound is not characteristic of short vowel words.
Let me know if you have any other words you'd like to analyze!