The secret is to focus on the beginning of the word:

• Включить — vklyuchit’ — turn on
  Выключить — vyklyuchit’ — turn off

  
  

The little prefix вы- often carries the idea of out or away, so when you see выключить, think of turning something off or taking it out of operation.

A couple of everyday examples:

• Включить свет – Turn on the light.

• Выключить свет – Turn off the light.

• Включить телевизор – Turn on the TV.

• Выключить телевизор – Turn off the TV.

  
  

Don’t worry about memorizing grammar first. Just hear these words over and over in real situations. Before long, your brain will automatically associate включить with on and выключить with off.

Sometimes learning Russian is simply about spotting a small pattern—and this is one you’ll use every single day.

Pronunciation tip: Listen for the difference at the beginning: v-klyu… versus vy-klyu…. That little вы- makes a big difference.