An indispensable book, very clear. After reading it, I bought it in 5 copies to distribute in my business. I also feel that all the profit will shoot my children. Lack a little star: the book does not address some issues of conventional spelling (eg the plural of compound words, classic pitfalls, but perhaps not that the "program" Voltaire). And an index would have been helpful for future quick reference (eg the agreement names / colors of adjectives is discussed in three places: the index would have been handy, again, this small flaw is probably due to the system ranking the difficulties of Voltaire Certification).
