F, or f, is the sixth letter in the modern English alphabet and the ISO basic Latin alphabet. Its name in English is ef (pronounced /ˈɛf/), plural efs. The Phoenician form of the letter was adopted into Greek as a vowel, upsilon (which resembled its descendant ‘Y’ but was also the ancestor of the Roman letters ‘U’, ‘V’, and ‘W’); and, with another form, as a consonant, digamma, which indicated the pronunciation /w/, as in Phoenician. Latin ‘F,’ despite being pronounced differently, is ultimately descended from digamma and closely resembles it in form.