That that is is that that is not is not is that it it is

"That that is is that that is not is not is that it it is"是一個表達歧義性以及標點符號的重要性的英文短語。

這句「句子」可以通過增加標點符號來分拆成四個句子：

還有一個分拆方法：

這是一個巴門尼德式的哲學諺語「that all that is, is, and that anything that does not exist does not.(存在的就是存在的，其他所有不存在的就是不存在的。)」這一個短語首先在裏出現，但在1959年的短故事"獻給阿爾吉儂的花束(Flowers for Algernon)"變得有名。Garylin(吉里連)在躺在草地上採摘雛菊以及自言自語時注意了它。

變體 

一個類似的短語，只有一句句子和一個標點符號：

意思：那個『這句句子「那似乎不存在的與那存在的不同」是錯的。』的想法是不對的。

還有一個類似的，長一些的短語：

還有一個有三句句子的短語：

意思：說某東西存在就等同說「那不存在」是錯的。

參見 
Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo
James while John had had had had had had had had had had had a better effect on the teacher
下雨天留客天留我不留
语言例句列表

參考資料 

语言游戏
语法
英语
歧義