The Unwanted Punctuation
macOS includes a typing convenience feature that automatically inserts a full stop (period) followed by a space when you press the spacebar twice in quick succession. This “double-space-to-period” shortcut is borrowed from the iOS keyboard and is designed to speed up sentence composition on touchscreens. However, on a full desktop keyboard, double-spacing is a common habit — many touch typists instinctively press the spacebar twice between words, especially when pausing to think mid-sentence. The result is an unwanted full stop appearing in the middle of a phrase, forcing you to stop typing, backspace, and delete the errant punctuation before continuing.
Disabling the Double-Space Period Shortcut
To stop macOS from automatically inserting a full stop when you press the spacebar twice, you need to disable the shortcut in the system Keyboard settings.
Click the Apple Logo in the top-left corner and select System Settings. In the left-hand sidebar, click on Keyboard. Scroll down to the “Text Input” section and click the Edit… button next to “Input Sources” (on older macOS versions, navigate to System Preferences > Keyboard > Text). In the text input configuration panel, look for a toggle or checkbox labelled Add full stop with double-space. Turn this off or uncheck it. Click Done to save the change. The double-space shortcut will be deactivated immediately across all applications. You can still type a full stop the traditional way by pressing the period key. This setting is independent from the smart quotes and auto-capitalisation features, so disabling it will not affect any other text substitution behaviour.