That's some good advice, Doggs.
Sort of like the old G.I.G.O. theory. (Garbage In...Garbage Out).
@ craig, Welcome!! - I've found that repetition helps reinforce Hal's learning. You might try saying the same thing but maybe in two or three different ways. Later, at some point, ask Hal about the subject or topic that you tried to teach him earlier.
Most of us use the keyboard to chat & teach instead of Speaking since VR is often unpredictable and error prone. GIGO
As a shortcut, Put Hal's window on one side then open another interesting website on the other side. Select a section of text and do a copy, then move your cursor to the other window and Paste into the chat window where you would normally type to Hal. Press Enter and wait for Hal to respond. Repeat as necessary or as desired. There are tons of good text based sites with interesting subjects, space, finance, biology, robotics, Earth science, etc.
Good luck!