Among the many misconceptions about CI, such as some mission against the Classics, “not teaching grammar while providing CI” is probably the most-cited, yet misinterpretissimus of misconceptions.
We teach grammar, oooooooh do we, although mostly in the context of complete Latin messages since even words/phrases contain grammatical information. There’s even explicit instruction, too, though brief student-initiated pop-up grammar explanations (e.g. “Mr. P, why does that word end with nt and not t?”) comprise most of this in a comprehension-based communicative classroom.
Still, even after all that, we do give explicit instruction when students are ready, usually in years 3 or 4. That’s right—even CI-advocating teachers explicitly teach grammar, and they do so using a host of methods and method-free strategies—all grammar-translation alternatives.
The problem, however, is when explicit grammar knowledge becomes the goal, and that instruction drives curriculum, assessments, grades, and enrollment. When CI-advocating teachers do teach grammar explicitly, it’s still not the foundation of class. Someone suggested that we could provide CI while focusing on a particular grammar point featured in a comprehensible story, and then using the story to have students build out the paradigm chart. Yes, we could, but the moment we shift focus to the language itself, we cease one thing and begin something else. With certainty, we can say that CI ceases to be provided except for when particular conditions are met. Most CI-advocating teachers, however, observe that students don’t meet these conditions. This shift has not shown itself to be beneficial for all kinds of learners. Some; yes. Most; hardly.
In the teaching grammar, there’s also an issue of goals. As far as I can tell (through my reading of the research, personal experience as student and teacher using grammar-translation, TPR, TPRS, and other method-free strategies to provide CI, as well as observations of other teachers/students), the only purpose of filling in a paradigm chart is to fill in a paradigm chart. Those who believe that filling in a paradigm chart results in students developing proficiency in the language are not looking at the same evidence I have been, or they haven’t had any experience to suggest otherwise.