Summary of the sources of Modern English "Y" Phoenician Greek Latin  English (approximate times of changes) Old Middle Modern     V → U → V/U/VV/UU → V/U/W Y → Y (vowel /y/) → Y (vowel /i/) → Y (vowels)     C → G → Ᵹ (consonantal /ɡ/, /j/ or /ɣ/) → Ȝ (consonantal /ɡ/, /j/ or /ɣ/) → G/GH Y (consonant)  An early Semitic version of the letter waw The later, Phoenician version of waw

The oldest direct ancestor of English letter Y was the Semitic letter waw (pronounced as [w]), from which also come F, U, V, and W. See F for details. The Greek and Latin alphabets developed from the Phoenician form of this early alphabet.

Since Late Middle English, the letter Y came to be used in a number of words where earlier Middle English spelling contained the letter yogh (Ȝȝ), which developed from the letter G, ultimately from Semitic gimel – as described below (As a side note - Modern Greek lowercase gamma ⟨γ⟩ is somewhat similarly shaped to the lowercase letter ⟨y⟩).

Vowel

The form of the modern letter Y is derived from the Greek letter upsilon. It dates back to the Latin of the first century BC, when upsilon was introduced a second time, this time with its "foot" to distinguish it. It was used to transcribe loanwords from the prestigious Attic dialect of Greek, which had the non-Latin vowel sound /y/ (as found in modern French cru (raw), or German grün (green)) in words that had been pronounced with /u/ in earlier Greek. Because [y] was not a native sound of Latin, Latin speakers had trouble pronouncing it, and it was usually pronounced /i/.[citation needed] Some Latin words of Italic origin also came to be spelled with 'y': Latin silva ('forest') was commonly spelled sylva, in analogy with the Greek cognate and synonym ὕλη.[1]

The letter Y was used to represent the sound /y/ in the writing systems of some other languages that adopted the Latin alphabet. In Old English and Old Norse, there was a native /y/ sound, and so Latin U, Y and I were all used to represent distinct vowel sounds. But, by the time of Middle English, /y/ had lost its roundedness and became identical to I (/iː/ and /ɪ/). Therefore, many words that originally had I were spelled with Y, and vice versa. The distinction between /y/ and /i/ was also lost in later Icelandic and Faroese, making the distinction purely orthographic and historical, but not in the mainland Scandinavian languages, where the distinction is retained. It may be observed that a similar merger of /y/ into /i/ happened in Greek around the beginning of the 2nd millennium, making the distinction between iota (Ι, ι) and upsilon (Υ, υ) purely a matter of historical spelling there as well. In the West Slavic languages, Y was adapted as a sign for the close central unrounded vowel /ɨ/; later, /ɨ/ merged with /i/ in Czech and Slovak, whereas Polish retains it with the pronunciation [ɘ]. Similarly, in Middle Welsh, Y came to be used to designate the vowels /ɨ/ and /ɘ/ in a way predictable from the position of the vowel in the word. Since then, /ɨ/ has merged with /i/ in Southern Welsh dialects, but /ɘ/ is retained.

In Modern English, Y can represent the same vowel sounds as the letter I. The use of the letter Y to represent a vowel is more restricted in Modern English than it was in Middle and early Modern English. It occurs mainly in the following three environments: for upsilon in Greek loan-words (system: Greek σύστημα), at the end of a word (rye, city; compare cities, where S is final), and in place of I before the ending -ing (dy-ing, justify-ing).

Consonant

As a consonant in English, Y normally represents a palatal approximant, /j/ (year, yore). In this usage, the letter Y has replaced the Middle English letter yogh (Ȝȝ), which could represent /j/. (Yogh could also represent other sounds, such as /ɣ/, which came to be written gh in Middle English.)

Confusion in writing with the letter thorn

When printing was introduced to Great Britain, Caxton and other English printers used Y in place of Þ (thorn: Modern English th), which did not exist in continental typefaces. From this convention comes the spelling of the as ye in the mock archaism Ye Olde Shoppe. But, in spite of the spelling, pronunciation was the same as for modern the (stressed /ðiː/, unstressed /ðə/). Pronouncing the article ye as yee (/jiː/) is purely a modern spelling pronunciation.[2]