What are all of the ways to turn down an invitation in Spanish?

To turn down an invitation in Spanish, you can say "Gracias, pero no puedo," meaning "Thank you, but I can't." Another option is "Lo siento, pero ya tengo otros planes," which translates to "I'm sorry, but I already have other plans." You could also use "Me encantaría, pero no puedo," meaning "I would love to, but I can't." Lastly, a simple "No, gracias" works for a polite decline.