Welcome to PokéCommunity! Register now and join one of the best fan communities on the 'net to talk Pokémon and more! We are not affiliated with The Pokémon Company or Nintendo.
Yes. If you battled a Starly [1 Speed EV] with your Gabite, you would get one Speed EV for Gabite. If you battled Starly with your Gabite while Staryu is equipped with an Experience Share, both Gabite and Staryu would get 1 Speed EV. It's actually one of the major strategies to EV train your team.