Disk space not freed after deleting files, unable to save things, unable to delete things, unable to update things Recently my Macbook Air has been saying "The disk you are attempting to use is full. Removing files and emptying the Trash will free up additional space." 

I have deleted everything in the trash, many other files, and 52 GB of photos. The only photos I have in my library now are 4.53 GB worth. When I click go to About This Mac it says I have 46 GB which is impossible. My computer is supposed to have a 121 GB Flash Storage with a 4 GB memory. 

In the past two days after deleting all my photos the computer isn't letting me save, delete, or update anything. Right now I have OS X 10.9.5. 

What can I do to fix this problem?
If you've "upgraded" to the Photo app from iPhoto or Aperture, your photos would have been imported as hard links. Basically this means that each photo is represented by both programmes and deleting from just one has no effect on the actual photo file. You'd need to delete from both.

Check to see if you have another album in your Pictures folder (or other folder if you manually placed it somewhere else) and delete the photos (hard links) there.