Early on with the Greybeards, the DB is told that for anyone NOT of dragon blood, it usually takes years to master just one word of a Shout. But when asking about how Ulfric defeated Torygg, DB gets told that essentially Ulfric "Shouted him to death". That seems to describe a three-word Unrelenting Force at least. So, if each word can take years, and Ulfric learned all three words, AND Ulfric is pointedly not dragonborn, just when did he spend nearly a decade studying with the Greybeards?

Other accounts say that Ulfric just knocked him down with the shout, then moved in to finish him with his sword. I suspect Ulfric only knows Fus, or maybe Fus Ro. I doubt he knows all three words of unrelenting force. But that would still be a few years of study. I'm not familiar enough with his timeline to know when he had time for that.

Hmm. I've NEVER heard any NPC mention Ulfric actually using a weapon on Torygg. No hacking, no bashing, no stabbing, no slashing, no blood, no gore. Just Ulfric Shouting and then Torygg was dead.

Have you talked with Ulfric about it? I'm pretty sure that's his side of the story--that he just knocked him down with the shout, then killed him with his sword.

Follow the link for http://www.uesp.net/wiki/Lore:Ulfric_Stormcloak if you want a few spoilers with regards to his lore. However, if you haven't done it yet, side with the Empire and when you get to have a little "chat" with Ulfric don't one shot kill him. Let him do some real fighting and

from last time I fought him, I think he knew Fus and Ro

and am positive he knew at least Zun as well since my sword flew across the palace

The http://www.uesp.net/wiki/Skyrim:Ulfric_Stormcloak confirms that he does know Disarm. It doesn't say how many words of each he has, though.

Yeah Ulfric himself says he shouted down Torygg and then stabbed him to death with his sword.

I would imagine Greybeards are chosen at a young age. Ulfric seems to be 45-50 years old.

Granted, I didn't pay much attention to what he actually used.

Note that it appears that Ulfric is the ONLY person that was present that stipulates that he finished Torygg off with a sword. Conversely, several other witnesses say that Ulfric "Shouted Torygg to pieces." I see no advantage that they could gain by describing the event as death by a single Shout, versus death by a Shout followed by the coup de grace upon a helpless opponent. If anything, I would expect them to harp on with the latter version, because it makes Ulfric look that much more of a could. Especially if that is the way it actually occurred.