One of the most frequent pieces of advice I find in the books for language teachers is “Skip [grammar issue X], because explaining it would unnecessarily overcomplicate the grammar part of your lesson”. Teachers are supposed to explain certain grammar topics to some extent and avoid others. My personal learning and teaching experience suggests otherwise. Adult learners (basically, everyone above 10 y.o.) memorize grammar better and use grammar rules more consistently when they fully understand what stands behind those grammar rules. By the way, it works for native speakers, too.
When it comes to your proficiency in a second language, knowing grammar is a bonus, but not a necessary thing. Like in fitness, knowing how muscles work doesn't make you slimmer or a better athlete. However, this may help you to make your workouts most efficient and to avoid injuries. The same applies to languages: knowing the rules doesn't make you a better speaker, but it definitely helps you get the most out of your lessons.
Should language lessons be linguistics-heavy? After all, most language learners want simply to speak a new language. They don't want to make an academic career. I think, language teachers should be frank and show language in its complexity to their students. However, this doesn't mean that teachers should spice their lessons with that academic lingo. Complex ideas can and should be explained in the simplest manner possible. If you can't so that, it is probably because you don't understand your subject well enough.
Avoiding complex grammar topics may humiliate and frustrate your students - either when they realize that you oversimplify things or when they encounter language in real life. It's the way you explain that matters, not the complexity of the topic.
When I explain grammar to my students, I try not to overload them with rules, but rather explain the rules. Of course, I can't tell my students why Russian nouns have this or that ending in each particular case, but I can explain the case system in general, and it helps my students to learn this subject faster. They still need hours and hours of practice, because this is how we actually acquire language, but at least, they understand what they are doing and are no longer scared.
This fall I attended a very nice course on astronomy. The course was for general public, so our lecturer didn't expected us, adult learners who just wanted to learn more about the night sky, to know anything about astrophysics. In ten lessons, I learned about physics and the stars more than I learned at school. Our lecturer explained physical processes in space, and of what's going on inside stars with very simple words, with accurate metaphors, yet, he never oversimplified a thing. He simply knew and loved his subject, and his enthusiasm was infectious. Instead of scaring or boring us with physics, he inspired his students to read more about stars. This is what great teacher should do – give an impulse for further learning.
When taking language lessons, do you want your teacher to explain grammar or do you want to keep lessons less theoretical?
Photo by Jinterwas