Files and folders question from noob

Hi,
Recent switcher here and I'm a little confused.
I have some files in my Documents folder. I've created other folders in my Documents folder to put these files in. For some files this works, for others it doesn't. Wth?
It seems like it's mostly .pdf files that I can't move into these folders I've created. Can someone explain what is going on?
Thanks,

-SR

**EDIT** Yup, it's .pdf's I can't move. Do I need Acrobat Reader installed to make this work or...?

You shouldn't need anything. You just drag and drop or save files wherever you want. What exactly happens when you drop a pdf into a folder? You've definitely tried dropping other kinds of files in those same folders? If no files are accepted, the folder could be locked for some reason.

Also, which Finder view are you using? Are you dragging files into the folders or copying and pasting? I'm trying to picture what you're doing in my mind's eye.

If I hold down click on a pdf, drag it to another folder and drop it, the file transfers to that folder as it should. As mentioned above, are you using another method?

I tried drag and drop and copy/paste.
And yes I could drag other files into that folder.
Oddly enough I just drag-n-dropped the files into another folder with no problem. And now I was able to drag-n-drop them into the folder I originally wanted them in. "Strange things are afoot at the Circle K"

-SR