&gt; Does this mean I can stand in front of a crowd and babble complete gibberish, and providing that my tone of voice and body language are good I&#x27;ll still get 93% of my point across?<p>Presuming a military or political speech, that sounds about right. Rousing speeches are still rousing even if you don&#x27;t speak the language they&#x27;re written in!<p>The point of a lot of presentations is effectively to dump a bunch of words that move the audience&#x27;s emotional state closer to the presenter&#x27;s emotional state. In &quot;emotional rhetoric&quot;, the body language and tone is primary; the words themselves are secondary, much like slides—they exist mostly to serve as a substrate for social-alliance signalling. (Imagine interactions between candidates during a presidential debate.)<p>The words in the speech <i>can</i> also aid the one-in-ten audience members who are too stubborn and analytical to be swayed by anything other than the facts. Even then, though, most emotional-rhetoric speeches usually have an accompanying leaflet&#x2F;programme&#x2F;manifesto&#x2F;whitepaper specifically for these people. A speech is almost never the proper place for the data to convince people of the soundness of the plan; instead, a speech&#x27;s proper role is in making clear what <i>emotional affect</i> the speaker holds toward the ideas they&#x27;re presenting. Which is, in a political environment, usually the most important thing to know about an idea: it&#x27;s the metadata that lets you know whether the idea is really going to be tried or not, caught up in bureaucracy or not, etc.