macOS Trackpad – How to Specify Dictionaries for Click and Press on Trackpad

Many people have tried to find the files for Apple's spell check dictionaries but I don't recall any successes.

As for the Language tab in Language & Text, it really doesn't have anything to do with spelling as such, although the top item on the list can set the default spell check dictionary in some circumstances. The top item on the list also sets the OS and app language (for the 22 that are available), the default collation order, and the preferred language requested by Safari. The order of the list can determine the app language used if a localization for the top item is not available. The order can also determine whether a Japanese or Chinese font is used for text which is ambiguous in that regard. I think adding an item to the list can sometimes provide additional encodings in Mail app.

I found this tool called BetterTouchTool http://www.boastr.net/

BetterTouchTool is a great, feature packed app that allows you to configure many gestures for your Magic Mouse, Macbook Trackpad and Magic Trackpad and also Mouse Gestures for normal mice. It also allows you to configure actions for keyboard shortcuts, normal mice buttons and the Apple Remote. In addition to this it has an iOS companion App (BTT Remote) which can also be configured to control your Mac the way you want.

It allows me to set a HUGE variety of actions for TONS of mouse gestures.

I am able to create actions for FORCE click on specific areas of the trackpad, and even multifinger force click. It is exactly what I've been looking for.

It is extremely useful.