I think that that that that that student wrote on the blackboard was wrong.
我认为那个学生写在黑板上的那个“that”是错误的.
第一个that是连词,引起宾语从句；第二、五个that是指示代词“那个”；第三个that在这儿相当于名词；第四个that是关系代词,引起定语从句.
你看懂这个就明白了
i think that
that that 那个that
that引起定语从句
that student 那个学生