Heta

Heta is a conventional name for the historical Greek alphabet letter eta (Η) and several of its variants, when used in their original function of denoting the consonant /h/.

The letter Η had been adopted by Greek from the Phoenician letter heth () originally with this consonantal sound value, and hēta was its original name. The Italic alphabets, and ultimately Latin, adopted the letter H from this Greek usage. However, Greek dialects progressively lost the sound /h/ from their phonological systems. In the Ionic dialects, where this loss of /h/ happened early, the name of the letter naturally changed to ēta, and the letter was subsequently turned from a consonant to a new use as a vowel, denoting the long half-open /ɛː/ sound. In this function it later entered the classical orthography adopted across the whole of Greece. According to traditional accounts, the new vowel, ēta, was originally the innovation of the poet Simonides of Ceos (556-468 BC).

In dialects that still had the /h/ sound as part of their phonological systems, including early Athens, the same letter continued to be used in its consonantal function. Just like vocalic eta, it could occur in a number of glyph variants in different local varieties of the alphabet, including one shaped like a square "8" similar to the original Phoenician (), but also a plain square (), a crossed square (), shapes with two horizontal () or with diagonal bars ().

During the classical era, more dialects adopted the new Ionian vocalic eta (as Athens did around c. 400 BC). As many of these dialects nevertheless still also pronounced /h/, they faced the problem of distinguishing between their own old consonantal symbol and the new vocalic symbol. Some dialects, including classical Attic, simply omitted the marking of the /h/-sound. In others (for instance Rhodes), the same symbol was used in both functions. Others distinguished between glyph variants, for instance in Delphi by using the closed square sign () for /h/, and the open H for the vowel. In the southern Italian colonies of Heraclea and Tarentum, a new innovative shape for /h/ was invented, consisting of a single vertical stem and a rightward-pointing horizontal bar, like a half H (). From this sign, later scholars developed the rough breathing or spiritus asper, which brought back the marking of the old /h/ sound into the standardized post-classical (polytonic) orthography of Greek in the form of a diacritic.

From scholia to the grammar of Dionysius Thrax, it appears that the memory of the former consonantal value of the letter Η was still alive in the era of the Alexandrine Koiné insofar as the name of the vocalic η was still pronounced "heta" and accordingly written with a rough breathing. The later standard spelling of the name eta, however, has the smooth breathing.

Διὰ τί τὸ η πρὸ τοῦ τ ψιλοῦται, ἐν δὲ τῷ ἧτα τῷ ὀνόματι τοῦ στοιχείου δασύνεται; Ἐπειδὴ παρὰ τοῖς ἀρχαίοις ὁ τύπος τοῦ Η ἐν τύπῳ δασείας ἔκειτο, ὥσπερ καὶ νῦν <παρὰ> τοῖς Ῥωμαίοις.

Why does η before τ have a smooth breathing, but in the letter name "ἥτα" [heta] it has the rough breathing? – Because in the old days the letter Η served to stand for the rough breathing, as it still does with the Romans.

Διὰ τί δὲ πάντων τῶν φωνηέντων ψιλουμένων, μόνου τοῦ υ φυσικὴν δασεῖαν ἔχοντος, τὸ ἧτα δασύνεται; Ὅτι πάλαι τὸ Η χαρακτὴρ ἦν τῆς δασείας· τοῦ Η τοίνυν χαρακτῆρα τῆς δασείας ἔχοντος, εὐλόγως καὶ τὸ ὄνομα αὐτοῦ δασύνεται· καὶ γὰρ ἄτοπον ἦν ἄλλοις χορηγοῦν τὴν πρόσπνευσιν τῆς δασείας αὐτὸ ταύτης στερεῖσθαι.