Polytonic

Greek orthography has used a variety of diacritics starting in the Hellenistic period. The complex polytonic orthography notates Ancient Greek phonology. The simple monotonic orthography, introduced in 1982, corresponds to Modern Greek phonology, and requires only two diacritics.

Polytonic orthography (from "much, many" and "accent") is the standard system for Ancient Greek and Medieval Greek. The acute accent (´), the grave accent (`), and the circumflex (ˆ) indicate different kinds of pitch accent. The rough breathing (῾) indicates the presence of the /h/ sound before a letter, while the smooth breathing (᾿) indicates the absence of /h/.

Since in Modern Greek the pitch accent has been replaced by a dynamic accent (stress), and the /h/ was lost, most polytonic diacritics have no phonetic significance, and merely reveal the underlying Ancient Greek etymology.

Monotonic orthography (from "single" and τόνος "accent") is the standard system for Modern Greek. It retains two diacritics: a single accent or tonos (΄), which indicates stress and the diaeresis (¨), which usually indicates a hiatus but occasionally indicates a diphthong: compare modern Greek (/pajˈðaca/, "lamb chops"), with a diphthong, and (/peˈðaca/, "little children") with a simple vowel. A tonos and a diaeresis can be combined on a single vowel to indicate a stressed vowel after a hiatus, as in the verb ταΐζω (/taˈizo/, "to feed").

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