A bit of both. As we all know, the words we chose are very important when making a speach. Often, for the sake of a fluid speach, I will substitute a word that works for the one that I can't think of. Just as I'm about to say it, though, a better word comes to me and then they come out as one jibberish-style word. So towards the begining of the speach I just freeze up and take a while to get through the speach. By the end, I'm making up words but am more comfortable in front of everyone. I can't seem to win.