These are:
(1) Sounds of the letters (vowels, diphthongs, consonants);
(2) Quantity;
(3) Accent.
[ SOUNDS OF THE LETTERS.]
[ Vowels.]
The vowels are five: a, e, i, o, u.
These when uttered alone are always long.
[Pompei. Comm. ad Donat. Keil. v. V. p. 101 et al.] Vocales autem quinque sunt: a, e, i, o, u. Istae quinque, quando solae proferuntur, longae sunt semper: quando solas litteras dicis, longae sunt. A sola longa est; e sola longa est.
A is uttered with the mouth widely opened, the tongue suspended and not touching the teeth: