In the Greek alphabet, there is no letter that directly corresponds to the English letter “J”. The Greek alphabet consists of 24 letters, and none of them represent the “J” sound as we know it in English.
The closest equivalent in Greek is the letter “Iota” (Ι, ι), which is pronounced like the “i” in “machine”. However, it does not have the same sound as the English “J”. The “J” sound is a relatively recent development in the history of the Latin alphabet and does not have a direct counterpart in the ancient Greek alphabet.
When Greek words are transliterated into English, the letter “Iota” is often represented by the letter “I” rather than “J”. For example, the Greek name “Ιωάννης” is transliterated as “Ioannis” in English, not “Joannis”.
In summary, the Greek alphabet does not have a letter that corresponds to the English “J”. The closest equivalent is “Iota”, but it represents a different sound.