Romanization of Greek is the transliteration (letter-mapping) or transcription (sound-mapping) of text from the Greek alphabet into the Latin alphabet.
History
The conventions for writing and romanizing Ancient Greek and Modern Greek differ markedly. The sound of the English letter B () was written as in ancient Greek but is now written as the digraph , while the modern sounds like the English letter V () instead. The Greek name became Johannes in Latin and then John in English, but in modern Greek has become ; this might be written as Yannis, Jani, Ioannis, Yiannis, or Giannis, but not Giannes or Giannēs as it would be for ancient Greek. The word might variously appear as Hagiοs, Agios, Aghios, or Ayios, or simply be translated as "Holy" or "Saint" in English forms of Greek placenames.
Traditional English renderings of Greek names originated from Roman systems established in antiquity. The Roman alphabet itself was a form of the Cumaean alphabet derived from the Euboean script that valued as and as and used variant forms of and that became L and S. When this script was used to write the classical Greek alphabet, ⟨κ⟩ was replaced with ⟨c⟩, ⟨αι⟩ and ⟨οι⟩ became ⟨æ⟩ and ⟨œ⟩, and ⟨ει⟩ and ⟨ου⟩ were simplified to ⟨i⟩ (more rarely—corresponding to an earlier pronunciation—⟨e⟩) and ⟨u⟩. Aspirated consonants like ⟨θ⟩, ⟨φ⟩, initial-⟨ρ⟩, and ⟨χ⟩ simply wrote out the sound: ⟨th⟩, ⟨ph⟩, ⟨rh⟩, and ⟨ch⟩. Because English orthography has changed so much from the original Greek, modern scholarly transliteration now usually renders ⟨κ⟩ as ⟨k⟩ and the diphthongs ⟨αι, οι, ει, ου⟩ as ⟨ai, oi, ei, ou⟩.
For treatment of polytonic Greek letters—for example, —see also the section on romanizing Greek diacritical marks below.
{| class="wikitable"
|-
! Greek
! title="Classical Latinate"| Classical<br/>
! title="Modern Scholarship"| <br><small>(2010)</small>
!
|-
| <big></big> || a || a || A
|-
| <big></big> || ae || ai || AI
|-
| <big></big> || b || b || B
|-
| rowspan="2" | <big></big> || g || g || rowspan="2" | G
|-
| || || || <br><small>(1962)</small>
! <br/><small>(1982; 2001)</small>
! <br><small>(2001)</small>
!
