Here's why:
* The vowel "i" in "dining" has a short vowel sound. It sounds like the "i" in "pin" or "win."
* Long vowel sounds are typically associated with a single vowel letter followed by a silent "e" at the end of the word. For example, "bike," "hope," or "time."
* While "dining" has an "e" at the end, it's not silent. It forms the final syllable, changing the sound of the "i" to a short vowel sound.
Therefore, "dining" is not a long vowel word.