The correct spelling of the phrase "study at different" is /ˈstʌdi æt ˈdɪfərənt/. The first word, "study," is spelled with a "y" and not an "i" because it is a verb, not a noun. The second word, "at," is spelled with an "a" and not "as" because it is a preposition. The third word, "different," is spelled with an "e" and not an "i" because it follows the spelling pattern of the word "differentiate." Proper spelling is important for clear communication in any language.