Everyone knows that the expression “dot the i” means “to clarify, clarify, bring to the end.” However, probably few people know about the origin of this idiom. It turns out that this is a borrowed phraseological unit that penetrated into Russian from the French language.
The French say, when they want to bring complete clarity to the conversation, "mettre les points sur les i et les barres sur les t".
The expression itself, linguists believe, appeared in the Middle Ages, since in Western European manuscripts the dot over i began to be written from the 11th century. In earlier sources, instead of a dot, a vertical bar was written. The appearance of a dot is explained by the fact that the scribes began to link letters to each other within words, and for visual differentiation from adjacent symbols, they began to put a dot.
According to the rules of writing, words should be written without taking the pen off the paper, and therefore dots are placed over i when the word is written entirely. That is, the work ends precisely by placing all the dots on the i.