How do I suppress my guns?
As a Counter-Terrorist, the game didn't automatically suppress my M4A1 after I bought it. How do I attach the suppressor?
What other guns can be suppressed?
The game didn't automatically suppress my M4A1 after I bought it
The weapons that have a silencer available should have it by default. Maybe you are confusing the M4A4 with the M4A1?
How do I attach the suppressor?
By equipping the weapon and using the alternate fire button (the default is Right Click).
What other guns can be suppressed?
The M4A1-S, USP-S and MP5-SD (for the later is not detachable).