In case you meant "под" (bulgarian "п"=latin "p"): "под"="under/below" ~ "sotto" "върху"="on"~"su" "на" is a synonym of "върху" and is actually the more used one (since it's shorter and more convenient), although, "на" is more universal - it has some other meanings too like "of" (for possessive preposition) or "to" (for direction).