“(?:(?!&[lr]squo;).)*”) # full set of doubles (no quotes inside) (?‘(?:(?!&[lr]dquo;).)*’) # full set of singles (no quotes inside) (?(?:(?!&[lr][sd]quo;).)*) # chars that are not quotes ) # end DEFINE ^ # Start of string (?: # Start non-capture group (?¬quotes) # Any non-quote chars &l(?[sd])quo; # Opening quote, capture single or double type # any full singles, doubles, not quotes or recursion (?:(?&single)|(?&double)|(?¬quotes)|(?R))* &r\kquo; # Closing quote of the correct type (?¬quotes) # )++ # Repeat non-capture group $ # End of string ~"; $string = "“He said ” ‘He said ’"; check_string($string); $string = "

“Wait a moment,” Jacey said. The street light lit up his aged, rat face. Who’s on the move?”

"; check_string($string); $string = "

“Wait a moment,” Jacey said. The street light lit up his aged, rat face. ‘Whos on the “move?” ’

"; check_string($string); $string = "

“He said he’ coming afer you,” Harry said, and he’ bringing the boys too!”

"; check_string($string); $string = "

“He ‘said he’ coming afer you,” Harry said, and he“ bringing the boys too!”

"; check_string($string); function check_string($string) { global $balanced_string_regex; echo (preg_match($balanced_string_regex, $string)) ? "Balanced!\n" : " Nah... Not Balanced.\n" ; }