Here's why:
* Vowel sounds: We need to consider the sound the word "magnet" makes, not just the letters. The first sound in "magnet" is a consonant sound ("m").
* Phonics: The "a" in "magnet" makes the short "a" sound, which is a vowel sound, but it's not the starting sound of the word.
Therefore, the word "magnet" doesn't start with a vowel sound.