This sound is /ā/, as in the word 'pain.' 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. By this point in Once’s curriculum, the instructional content renders this letter combination as ‘ai’ in Times New Roman font. In these middle stages of the curriculum, the instructional content will have phased out the specialized orthography that helped beginning readers (pre-kindergarten students through early elementary grades) learn letter-sound correspondence more quickly.