we don’t consciously pick the words we’re going to use. We don’t consciously form grammatical structure. It’s all done unconsciously – we just speak. In fact, when we speak, we know the gist of what we’re going to say, even though we don’t know precisely what we’re going to say until we say it.
Yes, we have a feeling of the shape of the thought, that we feel in one complete piece before the sequence of words used to express it

