How was your grammar before you start writing?

My grammar has always been fairly good--I think it's the result of YEARS of reading before I ever wrote for pleasure. If you want to improve your grammar, read, read, read. It really helps you get a "feel" for the language. And as for imaginative thinking, sometimes it's hard to stay out of it, lol. It can be so easy to go off on a mental tangent that leads me far from what I need to be focusing on at the moment. I write sad stories better when in a gloomy mood, and comedic stories better in a light mood; my mood determines the tone of the work.