Can you trade Pokemon to HeartGold?

You can't directly trade Pokémon to HeartGold. HeartGold (and SoulSilver) are Game Boy Advance games, and they can only connect with other Game Boy Advance games for trading.

Here's how you can get Pokémon from other games into HeartGold/SoulSilver:

* Using a Game Boy Advance (GBA) Link Cable: You can trade Pokémon between HeartGold/SoulSilver and other GBA games like Ruby, Sapphire, Emerald, FireRed, and LeafGreen.

* Using the "Pokémon Transporter" app: This app (available on Nintendo 3DS) allows you to transfer Pokémon from the Virtual Console versions of Red, Blue, Yellow, Gold, Silver, and Crystal to your HeartGold/SoulSilver games.

You cannot:

* Trade Pokémon from newer generation games (like Black & White, X & Y, etc.) directly to HeartGold/SoulSilver.

* Trade Pokémon from online services like Pokémon Bank or Pokémon Home to HeartGold/SoulSilver.

Let me know if you have any other questions about trading in Pokémon games!