他说那个男的写在黑板上的“that”用法是错的
He said 1that/ 2that that/ 3that/ 4that man wrote on the blackboard was wrong
数字1 是he said that 这个that是引导宾语从句
数字2 that that 是这个that 一个是指代这 that
数字3 引导定语从句
数字4 是 指代这个男人 对吧 哈哈