With all of my resources, I don't always have a hard grade that they're suited for, but usually I say for Core French anything from Grade 1 to 7, and then for French Immersion for grades 2-6. I know that sounds like QUITE the range, but I've been in the unique situation of teaching split grades for the last three years of my career, so all I have know when creating resources has been to make one resource and scaffold it based on the different grade ranges. I also have worked with enough students to realize that it is impossible to designate a resource to a specific grade as our students come to us with their own unique learning journey.