肯定句：Thatismyfather'skey.或者it'smyfather'skey. 　　否定句：Thatisnotmyfather'skey.或者itisnotmyfather'skey. 　　一般疑问句：Isitmyfather'skey?或者Isthatmyfather'skey? 　　特殊疑问句：Whosekeyisit/that?