... literally.

""" The Monkey Island movie never got the green light and years later Ted Elliott wrote 'Pirates of the Caribbean: Curse of the Black Pearl', which took several ideas from Monkey Island. So basically the first two PotC movies are the Monkey Island movie. """

http://monkeyisland.wikia.com/wiki/The_Curse_of_Monkey_Islan...

I've said it already on this thread but both MI and PotC, while influenced by each other (yes, MI is also influenced by the original pirates of the Caribbean ride) both have more in common with On Stranger Tides by Tim Powers. Ron Gilbert has stated in interviews that the book was a big inspiration, and the fourth PotC film is actually called On Stranger Tides and is essentially an adaptation.

The second and third movies also borrowed a lot from it, most memorably the scene where two characters get married during a swordfight is lifted straight from the book

That's a rather important part. Without it, everything else completely falls apart. And the only monkey didn't even have three heads.