Don't make a PDF just send file if you maden with other file in G drive!

http://goo.gl/sBCmwQ

in Google Docs, Sheets, and Slides files, and in other files, such as Microsoft Office files and Adobe  PDF files. People you work with can reply back, even if they’re not using G Suite. For example, if a co-worker opens a file using Microsoft Word they’ll see your comment in the file and can reply.


Instruction:

In  Google Drive a file and click Share plus > Enter the names of the people you want to share the file with.
> Click Edit  and select Can edit, Can comment, or Can view, depending on what access you want to give. > Make sure the Notify people box is checked and click send