i have 5 words of power left to find to complete the 60 total required for the 20 dragon shouts. Arngeir says, "There is only silence now ... perhaps later." Is he serious? Will he eventually give me the last 5 or am I to find them on my own. I wouldn't mind ... but as you know there are 3 possible locations for every shout (and they are not in order) and I didn't keep track of where I found the first ones --- eek. I might be able to eliminate some locations if they are marked as 'cleared', but I can never be sure that cleared for a quest and cleared for a shout were the same. Any advice?

Would he still tell you somewhere that's quest-locked? Like the mark of death wall in the DB sanctuary?

I don't think he will, but this hasn't really been confirmed.

He doesn't. I got every word wall that isn't stuck in a quest and he didn't tell me about word walls like the one in the DB sanctuary.

He only gives the words that don't have an entry requirement. Do the main quest, brotherhood quest (join or destroy - doesn't matter) and the Civil War quest and you should then have them all.

There are also a couple walls hidden in places you can only get to with quests from Companions, College of Winterhold, and Thieves Guild...

later you will get letters from a "friend" telling you where to find a word of power

You get those pretty randomly, but they seem to show up for me after using a shout in a relatively populated area, or in a dungeon (when outside of combat). Basically just Whirlwind Sprint thru town and you should get one.