It can happen that the option "Whole word" will stay checked even after Visual Studio 2015 is relaunched. A simple registry key modification can fix this problem.
In numerous editors, the shortcut
D duplicates current selection or current line. Visual Studio can't do that by default.
Thankfully Chris Lajoie developped a plugin to do that :
The default shortcut is
D but with a simple modification in shortcut settings you can use