Why cant my Jolteon learn Volt Switch?

Jolteon - #135 pokedex jolteon Jolteon Pokédex entries Kanto Versions, Pokédex entry Red, Blue, It accumulates negative ions in the atmosphere to blast out 10000 jolteon bulba Check out all the cards Jolteon appears on Back to Pokedex Showing Cards for: Jolteon Jolteon

jolteon bulbapedia Pokedex , Jolteon: “It accumulates negative ions in the atmosphere to blast out