Ubuntu 18: How to resolve conflict with CTRL layout switching and hotkeys?

Question

ubuntu

So once upon a time I discovered Punto Switcher for myself. It was like 10 years ago. Auto-switching the layout is yes, but in this program, in addition to all its functions, there is also a function for changing the hot key for switching layouts manually. And I chose left CTRL. Just press the left CTRL and the layout changes. This only happens when CTRL is pressed. If some other key is added (be it even Alt or Win or Shift, and even more so any hot key combinations in any program), then the layout does not change. It changes, as I said, only when I just (with my little finger imperceptibly) press CTRL. As I said, a lot of time has passed. The habit has become a habit.
It happened (there was a need) to learn and configure Linux. Installed Ubuntu 18.04.1 LTS 64-bit. There are several computers on the table, both machines are on the network, and therefore I immediately work both there and there (both on Windows and Line). But with the layout on Ubuntu, it's a complete mess. You can set the left CTRL toggle, but then none of the hotkeys work. And I am constantly in PyCharm and for me this is very critical. Tried to put CTRL + SHIFT, well, it's not convenient already, weaned. And when I put in the settings to switch on the left CTRL, then all the hot keys disappear. They are simply ignored, and the combinations turn like I don't press CTRL at all.
Those. for example, I press CTRL + C, but instead everything is erased and I see, like I just clicked on C . And so with all the keys.
Actually a question.How to teach Ubuntu to switch the layout by pressing the (naked) left CTRL, and to perceive and execute all combinations of any keys together with CTRL, in the normal mode of combinations?
ps
I tried to put Shift. Uncomfortable
Win - inconvenient (because I work in two systems, and in Windows Win calls the menu) I
even tried Shift + Caps. Well, it's inconvenient when you work in two systems. Constantly confused, and actually why?
After all, if there is a switch on the left CTRL in the settings, then you need to use it, you just need to tweak something so that the hot keys work.
Sincerely...

Answer 1

change hotkeys

Answer 2

I switch layouts using CAPS-lock - it doesn't conflict with anything.