What is the English of sana mag-aral kayong mabuti?

The most accurate translation of "Sana mag-aral kayong mabuti" in English is:

"I hope you study well." or "I hope you all study hard."

The "sana" implies a wish or hope. The "kayo" is plural, indicating "you all" or "you guys." "Mag-aral" means "to study," and "mabuti" means "well" or "hard."