Bengali–Assamese script
The script presently has 11 vowel letters, used to represent the seven vowel sounds of Bengali and eight vowel sounds of Assamese, along with a number of vowel diphthongs. All of these vowel letters are used in both Assamese and Bengali. Some of the vowels have different sounds depending on the word. There's a number of vowel distinctions who are preserved in the writing system but they are not pronounced as such in modern spoken Bengali or Assamese. For example, the script has two letters for the vowel sound [i] and two letters for the vowel sound [u]. This difference arised from the time when Eastern Nagari was used to write Sanskrit, a language that had a short  and a long , and a short  and a long . These letters are preserved in the script with their traditional names of "short i" and "long i", etc., despite that they are no longer pronounced differently in ordinary speech.