Steven used to stay up very late,didn't he?/usedn't he? 都可以Steven usedn't to stay up very late. Usedn't Steven to stay up very late? You'd better finish reading the book before your father came back home,hadn't you? You'd better not finish reading the book before your father came back home.Had you better finish reading the book before your father came back home?
The headmaster asked the students to have better take exercuse every day.