Hardly … When

• I had hardly closed my eyes when the phone rang.
• I had hardly closed the door before somebody knocked.
• I had hardly reached the station when the train steamed out.

In a formal or literary style, the structure is sometimes used with an inverted word order.

• Hardly had I closed my eyes when the phone rang.
• Hardly had I closed the door before somebody knocked.
• Hardly had I sat for dinner when the telephone rang.