Here's why:
* Short vowel sounds are typically associated with a single vowel sound followed by a consonant. Think of words like "cat," "dog," "pen," "cup," etc.
* The vowel sound in "sand" is a long vowel sound. It's the same as the vowel sound in "say" or "pay," which is represented by the letter "a" with a long "a" sound.
Therefore, "sand" is not a short vowel word.