I believe the AE pronunciation in gangster films and such like is often "ca-peesh", but of course the correct pronunciation is "ca-pee-sheh/shih".According to the OED, capisce derives from:
Italian capisce, 3rd person singular present indicative of capire to understand.
My very limited understanding suggests that this is also used as the formal 2nd person singular.
"Wikipedia English"Capisce is an Italian word that initially became popular in English in the 1940s, popularized by Italian immigrants in America's eastern cities and by use in onscreen portrayals of Italian-Americans, often in organized crime rôles.
It means "Get it?" and comes from the Italian verb capire, to understand. It is commonly mispelled and mispronounced, and has been rendered in English as "coppish," "capeesh," and "kapish," among other variations. Confusion about its meaning is memorably recorded in an episode of The Simpsons, in which a hardboiled supermarket security guard appends it to a warning to Bart.