The Accidental Deletion Mark
Google Docs relies heavily on keyboard shortcuts to accelerate the formatting process. While `Ctrl+B` for bold or `Ctrl+I` for italics are universally known, there is a lesser-known, highly disruptive shortcut: `Alt+Shift+5`. Pressing this combination instantly applies a strikethrough (a horizontal line drawn directly through the text) to whatever word or paragraph your cursor is currently highlighting. Because this shortcut involves commonly used modifier keys, users typing quickly, utilizing complex macros, or accidentally resting their hand on the keyboard often trigger it inadvertently, leaving random sentences crossed out as if they were marked for deletion.
Reverting the Strikethrough
To fix this formatting error and stop Google Docs from automatically striking through your text when you accidentally hit the specific keyboard shortcut combination, you must either undo the action or manually remove the formatting.
Unfortunately, Google Docs does not currently allow users to globally disable hardcoded system shortcuts like `Alt+Shift+5`. However, if you notice the text suddenly cross out while typing, the fastest fix is to immediately press Ctrl+Z (Windows/ChromeOS) or Cmd+Z (Mac) to undo the formatting application. If you notice the strikethrough later, highlight the affected text. You can either press the shortcut (Alt+Shift+5) again to toggle it off, or you can use the graphical menu. Click on Format in the top menu bar, hover over Text, and click on Strikethrough to remove the checkmark. For a complete clearing of all formatting on a highlighted section (including bold, italics, and strikethrough), press Ctrl+\ (backslash).