Indian script used to write the Sanskrit, Prākrit, Hindi, and Marathi languages, developed from the North Indian monumental script known as Gupta and ultimately from the Brāhmī alphabet, from which all modern Indian writing systems are derived. In use from the 7th century AD and occurring in its mature form from the 11th century onward, Devanāgarī is characterized by long, horizontal strokes at the tops of the letters, usually joined in modern usage to form a continuous horizontal line through the script when written. Devanāgarī is written from left to right and uses 48 letters—34 consonants and 14 vowels and diphthongs. In practice, the script—though alphabetic in origin—is syllabic, with a short a sound being understood after each consonant unless the sign for an alternative vowel is used; in the past, Devanāgarī was frequently written without the vowel signs, sometimes resulting in confusion.