I would like to point out at this moment that we are -supposed- to be testers of the game, not twenty questions experts/NPC mind readers. It is ridiculous in the extreme to worry about spoiling a 'quest' for someone when it is obviously spoiled already, and all the fun gone out of it by trying to guess -that- -one- -phrase-.
In other words, give out all the answers to all the quests there are now in a "Spoilers and Quest Answers" part of the guide or forum, so that folks can TEST to see if they work, not spend hours trying to guess what the bot wants you to say, only -then- to find out the quest is broke.
Once testing is over, and the NPCs can understand basic sentences, -then- go back to the guessing game.
This is why I never talk to NPCs.