I think writing it down in complete sentences is useful largely if you're a competent writer to begin with. I am, for instance, and when I write it's very simil

I think writing it down in complete sentences is useful largely if you're a competent writer to begin with. I am, for instance, and when I write it's very similar to how I talk normally, except that the thought process is more complete than when I'm extemporaneously chatting. What happens when I write down a planned talk is that I marshal all the ideas I have about what I want to say into a format that forces me to check what thoughts flow naturally into others, what doesn't fit anywhere naturally, and so on. As nlawalker points out, the trick is to not worry about staying on script. The point of a talk is the talking; otherwise you could just hand out copies of your transcript and there wouldn't be any point in putting everyone in the same room for 15 minutes. And talking, rather than reciting, is about the little "mistakes" and variations and spontaneous reactions you have to what's going in the room. Someone looks a little confused and you can choose to drill down on a point even if it's not in there. People look bored and you can cut something dry and unimportant.