This study is concerned with the teaching of French grammar to native speakers at the elementary level and specifically considers whether or not students are psychologically ready to handle concepts entailed in the formal instruction of grammar. The sample included 5,900 students in grades 4 through 8 in French schools in Ontario. Subjects completed the Test de Comprehension de Structures Linguistiques (Test of the Comprehension of Linguistic Structures). In addition, teachers were asked to complete a questionnaire concerning the curriculum followed. Results indicate that: (1) the linguistic structures included in grammar instruction are generally mastered before the child enters school; (2) the school program should build on this mastery; (3) students in the fourth, fifth, and sixth grades are generally not ready to acquire a formal and conscious understanding of grammar; (4) grammar instruction should be based on structures familiar to the child and should use examples rather than definitions; (5) the teaching of grammar as a system of symbols and rules governing the interrelationship of these symbols should be reserved for the seventh or eighth grade level; and (6) concepts taught in grammar should be redefined to eliminate ambiguity. Results support the consideration of developmental changes in grammar instruction. (CLK)