Do they have different pronunciations?
co-operation
cooperation
coöperation

Do these words differ in meaning and in use?coopération (also)

Question

Do they have different pronunciations?
co-operation
cooperation
coöperation

Do these words differ in meaning and in use?coopération   (also)

Answer

"Coopération" is French. I'm not sure what language "coöperation" is, but it's not English.

Answer

They are pronounced exactly the same way and mean the same thing, but we only use "co-operation" or "cooperation". Adding a diaeresis (oö) is not correct in this case.