Originally Posted by Icemage  |
(oh, and make sure it's an NPC and not a player - that can be confusing if you do it by accident  ).
Icemage |
Big way to avoid this is a little knowledge. When you start a trade to an NPC, the trade screen will pop up immediately. Starting a trade to a player puts something like "You offer to trade with Haggai" in your chat log. The player has to go and hit trade also to bring up the trade screen.
If you hit trade and the screen doesn't come up right away, you've attempted to trade with a player. Just /say mistake (using autotranslate is best, as who knows what language they speak) and re-attempt to trade to the NPC.