What principle explains that written language is made up of letters that represent sounds in spoken words?

The notion that written language is composed of letters that represent sounds in spoken words is encompassed by the alphabetic principle. This principle is foundational in understanding the relationship between graphemes (letters) and phonemes (sounds). It allows learners to decode written texts by recognizing that each letter or combination of letters corresponds to specific sounds in spoken language.

For example, knowing that the letter "b" corresponds to the /b/ sound, and "cat" has three letters that represent three distinct sounds, helps in reading and writing. Mastery of the alphabetic principle is crucial for developing literacy skills, as it enables individuals to blend sounds into words and segment words into their constituent sounds. This understanding forms the basis for phonics instruction and is essential for early reading development.