Command A - This command will select the entire document or every thing in a window

Command X- This will cut the selected text or files

Command V- This will paste the selected text or files

Command Z- Undo command /redo

Command D- Duplicate selected item

Command D- Eject the drive

Command M- Minimize all windows

Command-Delete- Move item to trash

Shift-Command-Delete- Empties the trash

Option-Command-W- Close all windows

Option-Command-Eject- Computer enters sleep mode

Command-: To display the spelling window

Command-; To check for spelling errors in a document