For example Razer Synapse can detect which keys you are pressing.
It also adds combinations like Ctrl + Shift and Ctrl + Alt and even differntiates between Right Shift/Alt/Ctrl which makes it possible for combinations like Shift + Right Shift or Ctrl +Right Alt.
Here's an example.
![Image](https://thumbs.gfycat.com/GregariousFamiliarAustrianpinscher-size_restricted.gif)