It is soft and harmonious, being highly vocalic in structure.
Every syllable is open, ending in a vowel sound, and short sentences may be constructed wholly of vocalic sounds.
Sumerian has a system of vowel harmony strikingly like that seen in all modern agglutinative languages, and it has also vocalic dissimilation similar to that found in modern Finnish and Esthonian.
The only consonants are k,1, m, n and p, which with the gently aspirated h, the five vowels, and the vocalic w, make up all the letters in use.
Vocalic harmony is the internal bringing together of vowels of the same class for the sake of greater euphony, while vocalic dissimilation is the deliberate insertion of another class of vowels, in order to prevent the disagreeable monotony arising from too prolonged a vowel harmony.
Tribes that of one family with another shows also that some are vocalic and soft, others wide in the range of sounds, while a third set are harsh and guttural, the speaking of them (according to Payne) resembling coughing, barking and sneezing.
Inflexion.The Portuguese article, now reduced to the vocalic form o, a, os, as, was to (exceptionally also el, which still survives in the expression El-Rei), la, los, las in the old language.
The alphabet was derived from the Doric alphabet of Rhodes, but ten other characters were added to it to express vocalic and other sounds not found in Greek.