[ElDiabloConCaca]

/bin/bash isn't a directory. It's a file -- more specifically, the bash shell.

/bin is a directory.

bash is a file in that directory.

If you copied something over the bash file in the /bin directory, then that's why your terminal doesn't work anymore. Unless you removed the whole /bin directory. You'd have to tell us what's there and what's not.

Do this: from the Finder, from the "Go" menu, select "Go to Folder" and type "/bin" at the folder prompt. Post a screenshot or list what you find in the resulting Finder window, or, in the case of an error message when trying to go there, post the text of the error message verbatim.