How can I debug this 'parse error' effectively? What tools or techniques can help?

Use a good code editor or IDE with PHP syntax highlighting and error checking. Examine the line number indicated in the error message carefully. Comment out sections of code to isolate the problematic area. Use `php -l your_file.php` from the command line to perform a syntax check without running the script. Pay close attention to the context around the `protected` keyword – is it within a class, a method, or global scope?