Formulae make the business of speaking (and that of hearing) easier. I assume that when a speaker uses a formula he or she needs only to retrieve it from the dictionary instead of building it up from its constituent parts.

While listening to a news broadcast on the radio, I began to tell an interesting story aloud. This ‘split attention’ task yielded an eerie experience. When I tried to speak fluently, the broadcast was reduced to gibberish, like the babble of peripheral conversation at a large cocktail party. It was unquestionably speech but was as meaningless as a poorly understood foreign language. Conversely, if I made a concerted effort to follow the gist of the newscast, my own speech became halting and repetitious and I lost the thread of my story.