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, had lost its roundedness and became identical to I ( and ). Therefore, many words that originally had I were spelled with Y, and vice versa. The distinction between and 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 into 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 . 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.