“used
to‖的肯定形式，疑问形式和否定形式： — I used to be afraid of the dark. —Did you use to be afraid of the dark? —Yes, I used to be afraid of the dark. —Did he use to be afraid of the dark? —No, he didn’t use to be afraid of the dark. 或 —Used you to be afraid of the dark? -- Yes, I used. / -- No, I usedn’t.