An Error Was Encountered

Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'or YEAR(stop)=) and (MONTH(start)= or MONTH(stop)= ) and lang='pl'' at line 3

SELECT start, stop FROM party WHERE (YEAR(start)= or YEAR(stop)=) and (MONTH(start)= or MONTH(stop)= ) and lang='pl'