How to copy and paste on MacBook Air

I always use the short cut keyboard for copying and pasting. Suddenly today my computer is not allowing me to do this any longer. Is there a setting I need to check or change. I use this feature all the time and very frustrated that I can't currently use it. PLEASE HELP!

Cut - Command+X

Copy - Command+C

Paste - Command+V

Copying, Cutting, and Pasting in OS X

You can easily copy, cut, or paste pictures, text, and other items easily using the built-in shortcuts and menus in OS X.

Copying text

To copy text, you can either secondary-click the text or use OS X’s built-in keyboard shortcut.

To copy using secondary-click, first secondary-click the text. Then, select the Copy button from the pop-up menu.

To copy using the keyboard shortcut, select the text. Then, press both the C and Command (⌘) keys at the same time.

Cutting text

To cut text, you can either secondary-click the text or use OS X’s built-in keyboard shortcut.

To cut using secondary-click, first secondary-click the text. Then, select the Cut button from the pop-up menu.

To cut using the keyboard shortcut, select the text. Then, press both the X and Command (⌘) keys at the same time.

Pasting text

To paste text, you can either secondary-click the text or use OS X’s built-in keyboard shortcut.

To paste using secondary-click, first secondary-click the text. Then, select the Paste button from the pop-up menu.

To paste using the keyboard shortcut, select the text. Then, press both the V and Command (⌘) keys at the same time.

Austin