"James while John had had had had had had had had had had had a better effect on the teacher" is an English sentence used to demonstrate lexical ambiguity and the necessity of punctuation,[1] which serves as a substitute for the intonation,[2] stress, and pauses found in speech.[3] In human information processing research, the sentence has been used to show how readers depend on punctuation to give sentences meaning, especially in the context of scanning across lines of text.[4] The sentence is sometimes presented as a puzzle, where the solver must add the punctuation.
You may remember an old classroom test in English language. What punctuation marks do you have to add to this sentence so as to make sense of it?
The object of this and similar tests is to make sense of a series of words by figuring out the correct intonation pattern.
Writing is secondary to speech, in history and in the fact that speech and not writing is fundamental to the human species.
In scanning across lines, readers also make use of the information parts carried along with the punctuation markes [sic]: a period, a dash, a colon, a semicolon or a comma may signal different degrees of integration/separation between the groupings.