How much did they pick up a Californian accent, Rob?
I've read that the VH brothers spoke Dutch when they were among each other.
Sammy Hagar used to think they were taking the piss off him when they spoke Dutch.
And I also read -from Dutch people who really talked with them- that their Dutch was the typical fifties version of the Dutch language, because that was what they brought with them to the USA. Makes perfect sense I guess. When you're not in touch with the community you leave behind, that's what happens. Language keeps changing en developing. New words are added and the archaic ones slowly disappear.