From the movie Charly

From the 1968 movie Charly, directed by  Ralph Nelson:

Charly asks his teacher to punctuate the following:

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

She declares that it makes no sense. It's a beautiful moment when Charly, then, shows off for the first time and adds punctuation marks to reach the following meaningful sequence:

"That that is, is. That that is not, is not. Is that it? It is."