"Du kan inte fly, pirater!" <- Incorrect
It's either one of the below:
"Ni kan inte fly, pirater!"
"Du kan inte fly, pirat!"
"ni" is "you" in plural (you-all).
"du" is "you" in singular.
"pirat" is one "pirate", and "pirater" is several "pirates".
But it was a good effort, nevertheless.