hsush

What do you mean with "castellano" vs "español"? I'm a native speaker and over here we call the language in general "castellano". For me the two words are synonymous (i.e. both refer to the general language, not to some specific dialect).

I don't think you're referring to anything remotely approaching bilingual speech. Educated English speakers might use "a priori" or "in vino veritas" or some word in French here in there, but those are tiny changes compared to how spanglish is spoken in Florida and other parts.