ABSTRACT
Although punctuation developed relatively late in the evolution of writing, it represents a cornerstone in the organization and functioning of writing, for both the writer and the reader. But, despite this, learning to use it remains a difficult task, and even the most educated adults occasionally make blatant elementary errors in punctuation. Fully literate (in the narrow sense of knowing how to use the letters of the alphabet) people may well find punctuation difficult. This difficulty involves the whole punctuation system and, in a quite particular way, the comma.
