The fundamental principles of an abugida apply to words made up of consonant-vowel (CV) syllables. The syllables are written as a linear sequences of the units of the script. Each syllable is either a letter that represents the sound of a consonant and its inherent vowel or a letter modified to indicate the vowel, either by means of diacritics or by changes in the form of the letter itself. If all modifications are by diacritics and all diacritics follow the direction of the writing of the letters, then the abugida is not an alphasyllabary.