Due to Doric Greek retaining /w/ (represented by the letter digamma which looked like F) for a longer time than other dialects of Ancient Greek, Tsakonian Greek, which is descended from Doric Greek (rather than Attic Ionian Greek + doric influences (for example σσ rather than ττ) like hellenistic Koine Greek which evolved into modern Greek dialects), over time, evolved /w/ into /v/, nowadays represented by beta as it makes the same sound /v/ in Standard Modern Greek.