This sound is /ā/, as in the word 'face.' Linguists call this kind of sound a diphthong. That means that it’s really a combination of two vowel sounds in one syllable. It starts as one sound and then moves to another. But even though /ā/ is a diphthong, we want students to recognize it as a single unit, so—as much as possible—try to treat it as a single continuous sound. The International Phonetic Alphabet (IPA) represents this phoneme with the following symbol: eɪ. In the early stages of the curriculum, Once’s instructional content represents the sound with a symbol that is made by typing ‘shift + a’ in a specialized font. This specialized orthography helps beginning readers (pre-kindergarten students through early elementary grades) learn letter-sound correspondence more quickly. By the middle stages of the curriculum, the specialized orthography is phased out and replaced by letters in a serif font.