Perdone or Perdon
This website says you should say "perdone" but in the pimsleur courses they just say "perdon" why the difference.
And why is it cómo está for the formal and not cómo está usted.
4 Answers
Perdoné, perdone, perdona are derived from the same word perdonar - to pardon
so it depends really who you're talking to:
- the "usted" form to be polite.
Por favor, perdoneme/perdone (usted) por abusar de su tiempo pero...
- the 'tú' form (more familiar)
Por favor, perdoname/perdona (tu) por abusar de tu tiempo pero...
Related thoughts...
What are the various ways to say "excuse me?" especially for use in the streets and subways of crowded cities where you need people to get out of your way?
What I hear and use in the streets and Metro of Madrid with all the crush of people are:
Perdon (pardon)
Perdoneme (pardon me)
Disculpe (excuse)
Disculpeme (excuse me)
And, another student in my Spanish class yesterday said that she uses:
Escusa (excuse ((me))
I also hear:
Permite (permit me to pass)
and, last but not least:
Pasa, pasa (which in use means, "Make way, I'm coming through.")

Thanks that makes sense
"cómo está" is short answer of "como está usted"
The informal use is "¿cómo estás?" ( esta with -s)