Look at the starter Pokemon you chose as your partner and think of the moves they possibly use. Which move would be a *star* move for them? Which one would they be using far often? (Like Ash's Pikachu uses Thunderbolt almost all the time, for example)
Hmm, kinda hard to answer, since a lot of the starters don't really learn moves exclusive to them, ie not shared with other starters of the same type. The only thing that really comes to mind actually, is Sceptile with its Leaf Blade. As for Pidgey though, I honestly can't think of anything other than Fly, and I just don't really know if that would cut it. I mean, most people seem to catch the Pidgey line, solely to have a Pokemon to fly them around, but they still learn so many moves and sdfjhfghdfg. I'd probably have to go with Fly though, but I feel like that'd also apply to other starter birds, as well as how most other starters don't really seem to get moves that are exclusive to them.