Originally, Hebrew was written without vowels, as can be seen on the Tel-Dan inscription and others.
See Joüon 41ff. For a discussion of vowels. There seems to be some connection between a and o sounds.
The original vowels are a, i, u as in other Semitic languages. E and o are modifications of these three where e arises from i or a and short o from u and long e by contraction from ai (ay) and long o sometimes by contraction from long a and sometimes from aw. GKC 35.
van der Merwe, 30 (he for o, a, e; waw for o and u; yod for i, e, e).
Vowels differ from one another in timbre (quality) and quantity (length of pronunciation). In Tiberian Hebrew—the Hebrew of the MT, “the latter [quantity] has no phonemic status.” No phonemic status means that you cannot change the meaning of a word by changing the quantity of the vowel. Also it means that there is no quantitative difference between, for example, patah and qames. Joüon, I.34. (see also GKC 40 where from the 24th German edition on the following note was included as a response to serious criticisms of its dealing with vowel quantity: “the Masoretes are not concerned with any distinction between long and short vowels, or in general with any question of quantity.” Therefore it appears that any idea of vowel length--as in quantity—is a left over from an earlier version of GKC. Though see Joüon, I.36 where he notes that this is Tiberian Hebrew and that as late as Jerome and Origen we can detect that quantity did have phonemic status. But again, “The only quantitative vowel distinction one can legitimately postulate for the Tiberian pronunciation is that between three of the seven ordinary full vowels and the corresponding three short vowels called hatefs… Joüon, I.37. “It is wrong to assume that a semantic distinction must necessarily be expressed by a phonetic one. Ambiguity is a common feature of any language.”
Joüοn also notes, “The distinction of five long vowels, ā, ē, ī, ō, ū, and five short vowels a, e, i, o, u, which was first introduced in its clasic form by Joseph Qimḥi (12th century) and generally accepted down to our times, is a radical alteration of the Tiberian vowel system. He was probably influenced in this by the Romance dialect he spoke himself or by Latin, or even by Arabic…, 38. See also 48ff.
See GKC, 49 where there is much more ambiguity in terms of which vowel belongs where. The same vowel in different words or marked by a matres lectionis (though not usually classed as unchageably long) can fit into a different class of vowel. So for example segol is first class and second class both. Patah is long and medium, etc.
Futato (and others) list this as an “a” class vowel, Futato 2.6.
1. Všetky slabiky začínajú so spoluhláskou
2. Okrem poslednej spoluhlásky v slove,
Samohláska alebo tichá šva vždy nasleduje
3. Každá slabika má jednu a iba jednu
samohlásku alebo polosamohlásku