Smooth breathing
It did not occur on an initial upsilon, which always has rough breathing (thus the early name ὕ hy, rather than ὔ y) except in certain pre-Koine dialects which had lost aspiration much earlier.The smooth breathing was kept in the traditional polytonic orthography even after the /h/ sound had disappeared from the language in Hellenistic times.The origin of the sign is thought to be the right-hand half ( ┤ ) of the letter H, which was used in some archaic Greek alphabets as [h] while in others it was used for the vowel eta.[2] In medieval and modern script, it takes the form of a closing half moon (reverse C) or a closing single quotation mark: Smooth breathings were also used in the early Cyrillic and Glagolitic alphabets when writing the Old Church Slavonic language.The coronis (κορωνίς, korōnís, "crow's beak" or "bent mark"), the symbol written over a vowel contracted by crasis,[4] was originally[when?]