What term describes the relationships between letters and sounds?

The term that describes the relationships between letters and sounds is phonics. Phonics is a foundational skill in reading instruction that helps children understand how letters are associated with sounds, enabling them to decode and read words. By learning phonics, students can recognize the sounds that correspond to individual letters and combinations of letters, facilitating the process of word recognition and reading fluency. This focus on the sound-letter relationship is crucial for developing early literacy skills, as it allows children to apply their knowledge of sounds to new words, enhancing their reading capabilities.

The other options each refer to different linguistic concepts: syntax deals with the arrangement of words to form sentences; morphemes are the smallest units of meaning in a language; and the lexicon refers to a vocabulary of a language, including its words and expressions. These concepts, while important in the study of language and literacy, do not specifically address the connection between letters and sounds as phonics does.