Here's why:
* Spelling: The "a" in "cast" is followed by a consonant ("s") and a silent "t". This combination often indicates a long vowel sound.
* Sound: The vowel sound in "cast" is the same as the vowel sound in words like "car" and "father". It's a long "a" sound.
Short vowel sounds are typically found in words like:
* Cat
* Dog
* Hop
* Sun
Let me know if you'd like to explore more about vowel sounds!