estúpido

Fue una decision estupida que le costo muy cara.

It was a stupid decision that cost him dearly.

No digas cosas estupidas delante de los ninos.

Do not say stupid things in front of the children.

Ese plan es completamente estupido y no funcionara.

That plan is completely stupid and will not work.

Me siento estúpido por haberlo olvidado otra vez.

I feel stupid for having forgotten it again.

No seas estúpido y escucha lo que te digo.

Do not be silly and listen to what I am telling you.