New Software

• If you recently installed new software or upgraded existing major software, such as your operating system, any preferences you previously set for your shortcuts may not have survived the transition. To fix this error, choose the "System Preferences" icon or the link to system preferences in the Apple menu. In the Keyboard settings, select the "Keyboard Shortcuts" link near the top. From this pane, click "Restore Defaults" and your computer reassigns the standard shortcuts.
  
  

External Keyboards

• If you are using an external keyboard with your MacBook, such as a Bluetooth keyboard, you may need to configure your external keyboard's settings from the same area of System Preferences as the built-in keyboard. External keyboards may not support shortcuts, particularly if they are designed for Windows or other operating systems. If the shortcuts work on your built-in keyboard but not an external keyboard, this is most likely the case.
  
  

Program-Specific Shortcuts

• After resetting the general shortcuts to the default in System Preferences, you may need to restore the default shortcuts or your personal settings for keyboard shortcuts in individual programs. For example, Pages, Word for Mac, iMovie and Final Cut all have their own keyboard shortcut settings. Use the menus within each program to restore your default settings.
  
  

Other Troubleshooting Options

• A minor software glitch may cause this problem, and can often be corrected simply by restarting your MacBook. You may also want to check for new software updates if you have not updated recently, as you may be encountering a bug that an update will fix. If a recent update seems to be the cause of the problem, try uninstalling and reinstalling the software in question.