The Linguistic Surprise
Ubuntu supports multiple keyboard layouts and input sources out of the box, which is invaluable for multilingual users. However, if you have more than one input source configured (for example, English UK and Tamil), Ubuntu may automatically switch between them at unexpected moments. This often happens when you press the Super (Windows) key combined with the Space bar, a default shortcut for cycling input sources that is easily triggered accidentally. One moment you are typing an email in English, and the next, every keystroke produces characters from a completely different script, leaving you staring at a garbled sentence wondering what went wrong.
Locking Your Keyboard Layout
To stop Ubuntu from automatically switching your keyboard layout when you accidentally press the input source shortcut, you need to either remove the shortcut or remove the additional input sources entirely.
Open the Settings app and navigate to Keyboard. Scroll down to the Input Sources section. If you see multiple input sources listed (e.g., “English (UK)” and another language), and you only need one, click on the unwanted input source and press the minus (−) button to remove it. With only one input source remaining, the switching shortcut becomes inert. If you genuinely need multiple input sources but want to prevent accidental switching, scroll up in the Keyboard settings and click on Keyboard Shortcuts. Navigate to the Typing category. Find the shortcut labelled Switch to next input source. Click on it and either press Backspace to clear the shortcut entirely, or reassign it to a more deliberate key combination (such as Ctrl + Shift + Space) that is harder to trigger by accident.