Maybe many friends don't know the background of most formal speeches. Because the formal speech is broadcast live, the speaker will try to avoid making mistakes. Therefore, most speakers will have special manuscripts and special teleprompters. Some people may think that a person with good eloquence does not need a teleprompter at all, and a person who has experienced many elections like the president of the United States does not need a teleprompter. No, it is because he is the president that he wants to use the teleprompter.
Of course, the speaker's personality will also have an impact on the style and effect of the speech. A careless president like Trump often just takes the manuscript as an outline, integrates most of his ideological elements into the text, and expresses it at will during his speech. Sometimes he even finds the manuscript boring and throws it away. So Trump often makes mistakes, and sometimes he doesn't even find out. The last sentence he said doesn't match the next one, because the manuscript is different from his own ideas.
No one is born to speak, and no one is born with this ability, relying on repeated tempering, repeated experience summary and their own diligence. However, as a president, there are countless occasions to go in and out every day. Every time, words and language will change with different occasions. At this time, manuscripts and teleprompters are even more needed.