un runing
sit sitting
put putting
cut cutting
stop stopped
一个元音加一个辅音结尾并且重读时(重读闭音节)要双写
还有重读r音节 refer referred
prefer preferred
un runing
sit sitting
put putting
cut cutting
stop stopped
一个元音加一个辅音结尾并且重读时(重读闭音节)要双写
还有重读r音节 refer referred
prefer preferred