Trick or treat
Halloween, as you know it in Spain, is an American import. However, it has it roots in Celtic culture.
The saying Trick or Treat is translated as Truco o Trato. I think this is a mistake.
Trato should be translated as a deal or an agreement not treat.
A treat is something special you do or buy for someone else. In the case of Halloween, the treat would be the sweets that the children are given. I'm not sure but I think you'd translate it as gusto or invitación.
Treat is also a verb.
- I was feeling a bit down so I treated myself to some chocolate biscuits.
- He treated his wife to a weekend away in Paris.
- If you behave, as a special treat, I'll take you to the park to feed the ducks.
When did you last treat yourself to something?
When did someone last treat you to something?
Did you celebrate Halloween?
What did you dress up as?