Here's why:
* Short vowels are usually found in one-syllable words where the vowel sound is short and quick. Examples include: cat, dog, hop, and sit.
* Pencil has two syllables: pen-cil. The first syllable "pen" has a short vowel sound, but the second syllable "cil" has a long "i" sound.
Therefore, "pencil" is not considered a short vowel word.