The real Grammaire progressive isn't a free PDF—it's the progress you make in your head. (But if you're a student with no money, ask your library or a classmate. Don't wake the Conditional.)
is a flagship grammar resource for students of French as a Foreign Language (FLE). Published by CLE International
: Multiple editions, including the 4th edition, are hosted on Scribd (may require a subscription or document upload for full download).