In Construct 2 various actions had hotkeys assigned to them, and they had a reminder text so you'd know what you could press. Hotkeys allow for making more efficient progress when making games.
Construct 3 still has hotkeys, but they're a secret. I don't think there's a way to learn them as easily, or find out which things can be accessed with them.
Here are the ones I use, that I can remember with muscle memory from using C2 and from experimentation, in event sheets:
• Q = Comment
• V = Variable (local or global)
• S = insert Subevent
• B = insert Blank subevent
• C or E = add a Condition
• A = add an Action
• D = toggle Disabled
• R = Replace object