I worked as an industrial adult educator for twenty years. My teaching credentials were granted by California in 1980. I have dealt with adult literacy on a regular basis teaching adults some pretty complex mechanisms and systems. I trained employees in the Federal regulations governing rail transportation operations (operating rules) and maintenance regulations. My signature was placed on Federal documents as proof the employee met the standard and knew how to do the tasks. I flunked a number of employees who could not read well enough to learn what was expected, or who could not read well enough to take the required tests. I can spot a non-reader in a minute, just by watching how they read and how they respond to simple comprehension questions.
This website (ACP Internist) describes the problem and how to spot it. The following was printed in the April 2000 ACP-ASIM Observer, copyright © 2000 by the American College of Physicians-American Society of Internal Medicine. (Emphasis is mine.)
Here are some tips to identify patients with reading problems and how to help them:
Look for signs. The first step is to identify patients who are functionally illiterate: unable to read and understand how to take medications or when to come in for a follow-up appointment. But experts say that identifying illiteracy is not always easy. You can’t depend on appearances; many well-dressed, even articulate patients have literacy problems. “You won’t see illiteracy unless you look for it,” said Dr. Parker.
Fortunately, though, there are some fast, easy ways to help confirm your suspicions that a patient may have literacy problems. Dr. Parker, for example, carries a pill bottle with her. “I take it out and ask patients to read it and tell me how they would take the medication,” she said.
Another technique is to tell your patients you want to test their vision and ask them to read a few sentences from a pamphlet. If they give you the age-old excuse that they left their reading glasses at home, be wary.
Here are a few videos proving the point that tRump does not read very well (or at all):
Uh-Oh: Does Donald Trump Know How to Read? by David Pakman
Note at 8:39, when asked to read a document, he says he needs his glasses.
WOW: Trump Fails Basic Literacy Test by David Pakman
Donald Trump and Literacy by Steve Kaufmann
This leads us to examining the limited (some say as few as 800 words) vocabulary he uses while speaking:
Donald Trump Speaks At A 4th Grade Level