I am used to staying up till late at night . | The doctor sat up all night with the sick old man . | I stayed up till late at night . I'm awake . I stayed up late last night . As it is , I am awake . I stayed up all night . I sat up till late last night . Coffee keeps me awake . At that time , I was still awake . I sat up reading till late last night . You ought not to stay up so late . I stayed up till very late last night . I often stay up all night . |