Before anyone knocks me down I �d like to say that the following answer is from my own living/breathing experience and not from a dictionary.  Therefore, it is what is commonly used in the area that I live/work in which might be different to other countries or other people �s perceptions based on dictionary definitions.

 

I only ever hear the word �collaborate � in formal situations such as business tenders or reports on teams/companies collaborating (working together).  IMHO it �s not a commonly used word in everyday English in the circles that I mix in.  In informal situations people usually say work together.  I rarely hear the word co-operate informally either.  When some-one co-operates there is usually trouble brewing  e.g. he co-operated with the police

 

In the business sense co-operate and collaborate have different meanings.  It depends on your context.

 

Cheers

 

Jayho

 

I think your answers are great and very complete !

 

But maybe, sometimes it can help to think, just quick, about the composition  of the two words

 co = together

operate = do something /change the state of something

labor = work (often for money, or gain in someway.... or out obligation !) ( you would never speak of slave operating, would you? -  Only slave labor)

 

 

- (it �s only out of own reading experience) :

 

       I would only use collaborate with the ennemy in a negative way: benefit for the only person collaborating : out of fear or greed.

       I would use cooperate with the ennemy when both parts hope thus, for a better common result for both parties.

 

Nighty night ..... hope the bugs don �t bite .....