How to Empty Your Mac Trash
Even though you’ve deleted documents, if not entire folders, they reside in your Mac trash can. To free up hard drive space, you need to actually empty your Mac trash.
Start by moving any documents you want to delete to the Mac trash can. Use the mouse to drag the document icons above the trash can in the dock. Release the mouse button when the trash can turns black. (Alternatively, press Command+Delete or choose the File and then Move to Trash commands.)
You’ll know you have stuff in the trash because the icon shows crumpled paper. To completely empty your trash can, choose Empty Trash under the Finder menu or press Command+Shift+Delete. A warning will pop up, reminding you that once your trash is gone, it is gone.
If you’ve changed your mind, as long as you haven’t selected Empty Trash, you can click the Trash icon to recover your trashed documents. In the list that appears, simply drag the document back onto the desktop or into the folder where it used to reside.
If you’re absolutely, positively certain that you want to get rid of the contents of your trash choose Secure Empty Trash from the Finder menu instead of the regular Empty Trash command.