When I was working as language teacher, I was tasked specifically with teaching speaking. I would often use information gap activities. These are activities where two or more parties have pieces of information but need to obtain pieces from others in order to complete the task. Sometimes, these would us language forms (re: sentence structures), but most of the time they were free flow activities. It didn't matter how "correct" the language was so long as the idea was communicated.
To think about it another, how often do we make mistakes when speaking? Writing? And yet, we still managed to communicate just fine.
That's not to say there shouldn't be any focus on form, but simply that it's not nearly as important as many tend to think when it comes to language learning.