Open Facebook and go to Settings & privacy
Tap Settings
Open Blocking
Check the Block users list
Search for the person’s name in the blocked list
Go to the person’s profile if you can find it through search
If their profile does not appear in search, you may have blocked them
If you can see a Block option instead of Unblock on their profile, they are blocked
If you see Unblock in the Blocking list next to their name, they are blocked
If you cannot message, tag, or add them, they may be blocked