"Yo hablo espanol perfecto. Nunca estudié lo. Pero todos mi amigos me dizen q hablolo al perfección. Que os parece este....este....afirmación. Todos ustedes no sepan nada de essio. 

Note the mixing of the vosotros and the ustedes and improper placement of articles, not to mention the lack of concordance between nouns and adjectives and gender."

This doesn't make any sense, because any person who has spent any significant amount of time around the Spanish language will intuitively KNOW that all of that is wrong.  You don't have to teach it.  And if the issue is spelling (which many of the errors here are), the solution is more reading.  I think grammar can serve as a guide or a model, so that beginning learners have an idea of where they need to go, etc.  But it's just a guide.  Saying grammar instruction is equivalent to language learning is like saying that the map is equivalent to the road.  Completely off base.  

I totally agree with Antonio when he says that when it comes to grammar instruction, "less is more".  Gracias Antonio por compartir tu experiencia y conocimiento.