Sable

This achievement is quite simple and you'll get it naturally throughout the game as you play through the story. You can't get it straight away in the Ewer as there aren't enough people to talk to but keep playing through the game and as you explore new areas, new NPC's become available.

If you're going for Silver-Tongued Sable (Talk to 30 NPC's) then you will of course get this one along the way. Make sure to check out the Silver-Tongued Sable achievement and look at the excellent guide provided by ICE Faux Pirate. They have a list of basically every NPC in each location of the game.

Again this achievement will naturally pop reasonably early as you play the game. If you are going for other larger achievements or simply just enjoying Sable's story and scenery, you can sit back and let this one unlock naturally.