I don't really see the point in trying to force someone go learn all the vocab right up front. I've only been sailing for a couple of years and still don't know many of the correct terms, yet still manage to get the boat where I want to go. (I do know what the mainsheet is). Almost everyone I've sailed with to date has zero experience as well. When I want them to do something I just point at it and say "pull in that rope", "let out that line", ect... Terminology is irrelevant as long as they are doing the write action, as time goes on they will learn what your talking about. While they are performing the action you could then inform them what the name of the line is and next time they might have less of a dumb look on their face.
I have to disagree. I may point and say "release ("blow") The traveler" (for example), but I will use the correct term and explain that "Blow" means release, and why they just did it. I don't know what size boat you are sailing on, but when you point to a bank of lines and clam cleats and say "release that line" it simply may not work. Communication is important, and proper terms are essential to communication IMO.
Another suggestion is get them to take a sailing course. They will learn a lot faster that way then being trained by you, for the simple reason that it removes the emotional aspect from the equation. Plus if they mess up something its not on your boat.
Again, I disagree. Sailing courses can certainly be beneficial (especially if you know you are an "emotional, excitable, etc." teacher). However, I can't tell you how many "crew" I've had on my boat with multiple certificates (Keel boat, etc.) who were fairly worthless when they boarded. More than once I've been told...."I learned more this afternoon sailing with you than I ever did at Such And Such school of sailing" (and most are reputable schools). Often, they simply don't get the amount of one on one instruction and hands on experience with a school that they do on my boat, which is understandable. In addition, time is money, and it's obvious that several schools issue "diplomas" before the student has a grasp. So, I can assure you, a "degree" in sailing doesn't mean you know how to sail! With all due respect, the fact that you have been sailing for a couple of years and don't know the terms may be evidence of this. In any case, I would certainly refrain from giving advice on teaching until you at least know all the terms! Properly and safely sailing a boat means more than getting it from A to B. Fortunately, lots of wisdom is available from experienced Skippers in this forum. IMO, the trick is to know when to read and when to post (or at least post a question as the OP did).