Finder may show a file as “Workshop” even though its full name ends in .pdf. If you need the exact name for a handoff, reveal the extension through Finder settings or file information. The choice depends on whether you want to inspect one item or every file Finder shows.
Check a single file
Select a familiar file and press Command-I. Expand Name & Extension. Clear Hide extension if you want Finder to show this file’s suffix. For example, a project folder might contain Workshop.pdf and Workshop.pages. With the suffixes visible, the file you should attach is easier to identify. Check the full name in the Info window before sharing it.
Show every extension
In Finder, open Finder → Settings → Advanced and select Show all filename extensions. This setting overrides a file’s Hide extension checkbox. When you turn the global option off, Finder uses the individual setting again. Compare the same two known files before and after so you can tell which setting is active.
These controls affect the name Finder displays. Keep the suffix intact when editing the rest of a filename. Finder’s warning for changing an extension is a separate option on the Advanced pane.