I think it was Scott Thornbury who brought to my attention the way repetition can increase grammatical accuracy; Actually I the idea from Uncovering Grammar but the linked blog post has a nice summary of all the benefits of having students repeat, along with some ways to do it while keeping the lesson interesting. And I recently had a personal experience that really brought it home for me.
I was recently visiting my wife’s family, who speak Russian only. I had told a story in Russian to my wife, who is far more used to my brand of pidgin Russian. Later that morning, as I was waiting for lunch, I found myself repeating the story in my head, looking for better words, rethinking grammar choices. Whereas the version I had told my wife a few hours before had been spontaneous and thus full of mistakes, I now had a chance to prepare. And while the communicative focus of the contemporary classroom holds that students must learn to speak without preparation, “just like in the real world”, I am surprised when I reflect on it, just how often I do prepare what I am going to say and how often I am repeating some version of something I said before whether it be a funny story, an inside joke with a friend, an explanation of how to do something, or a piece of standard social text.
It seems to me that giving our students chances to repeat is giving them chances to prepare, at least on a subconscious level. And giving them a chance to prepare is giving them a chance to repeat, even if only the words in their heads. And both thinking before speaking and saying the same thing twice are perfectly normal things to do outside the classroom. So why not inside the classroom?