Sorry for not answering for such a long time, I don’t visit this website and haven’t got any email notifications.
Probably, you using it in a wrong way. I’ve just installed clean WP 3.8.1 and this plugin (via WP admin panel) – it works out of the box.
The workflow is as follows:
- You add some “Tags” (or any other custom taxonomies) to your first post. These obviously won’t be autocompleted, as you haven’t got any data yet.
- Then you start editing some other post and try adding the same taxonomies. And these will be autocompleted.
Basically, the plugin does autocomplete using your data, not some English dictionary.