Fuck
One of the most versatile words in the English language. It can be used as a noun, a verb, an adjective, an adverb, and an exclamation.
E.g.
Fuck off! - ¡Vete a tomar por culo!
What a fucking drag! - ¡Menudo rollo!
I don't give a fuck- Me importa un carajo
You are a fucker- Eres un hijo de puta