In Pokemon Pearl, you can restore your Pokemon's PP by:
* Visiting a Pokemon Center: This is the most common and reliable way to restore PP.
* Using a PP Up: This item increases the maximum PP of a move by 20.
* Using a PP Max: This item increases the maximum PP of a move to its maximum potential.
If you're looking for a way to restore your Pokemon's PP in Pokemon Pearl, you'll need to stick to these methods.