What term describes two letters that combine to make one sound?

The term that describes two letters combining to make one sound is known as a digraph. A digraph is a specific phonetic unit that occurs when two letters work together to represent a single sound, which can be a consonant sound, such as “sh” in "shoe," or a vowel sound, like “ea” in "bread."

Understanding digraphs is important in the study of phonics and contributes to effective reading and spelling strategies, as it facilitates the recognition of these sound combinations within words. This concept is crucial in speech-language pathology, particularly when developing reading and literacy skills in learners.

The other terms do have distinct meanings: a trigraph refers to three letters that create a single sound; a blend involves two or more consonants that are pronounced together while retaining their individual sounds, such as "bl" in "black"; and a monograph is a detailed written study of a single specialized topic, which is unrelated to the phonetic concepts being discussed.