Orthographic depth
Orthographic depth is how much one-to-one relationship there is between the sounds of a language and the letters used to write them, or how much a word is spelled the way it sounds. Writing systems with a close one-to-one relationship between sounds and letters are called orthographically shallow writing systems. This includes the Spanish alphabet, Japanese kana, the Finnish alphabet, the Turkish alphabet, and the Italian alphabet. In these languages, it is easy to figure out how to speak these languages simply by reading them. Writing systems with little one-to-one relationship between sounds and letters are called orthographically deep writing systems. These would include the English alphabet, French alphabet, Mongolian script, and Thai script.