What language mistakes are and why we all make them Hi everyone! I am supposed to write an abstract for a conference and that's the first time I write something like that. Could you help me to correct it please? Thank you so much!!! In light of Frei's grammar, I will explain what mistakes really are and why we all make them. The author of the book analyses the French language from a functional point of view and opposes faute (mistake) and déficit (deficit), two essential concepts within his theory. Given their proper definitions, I will demonstrate why mistakes do not represent a weakness for a given language. On the contrary, they seek to break the artificial rules imposed by the normative system, in order to render the language more consistent and communication less complicated for the speakers. Finally, I will discuss the five fundamental principles that guide each natural language in the world, namely analogy, clarity, economy, invariability and expressivity. For each of these principles, I will give concrete examples of their functioning and analyse their importance in oral and written language.