Excuse my French

In Spanish, when you want to refer to something like a wind travelling in your belly, you say pedo. This ungracious little word is seldom used alone but it has become part of a series of phrases that occur with incredible frequency.
For example:
* estar en pedo: be drunk / crazy
* estar al pedo: be useless
* de pedo: by sheer chance
* ni en pedo: no way

How to use them:
* Marcos está en pedo.
* Estuve al pedo toda la tarde. (doing nothing)
* Tuve un accidente y me salvé de pedo.
* - ¿Vas a ir a la fiesta esta noche?
- Ni en pedo.

Advice: if you're trying to sound refined, don't use them.