The correct spelling for the phrase "study at masterful" is /ˈstʌdi ət ˈmɑːstərfʊl/. The "study" is pronounced as "stuh-dee" while the preposition "at" is pronounced as "uht". "Masterful" is pronounced as "mah-stuh-ful". The word means to learn or immerse oneself in a subject with skill and expertise. To study at masterful means to learn from an expert in a particular field, and to gain proficiency in a specific subject through dedicated practice and effort.