Explanation: Had I been a king, I would have helped the poor.
Conditional sentence- এ Had + Sub + V3 + Ext. এভাবে কোন Sentence শুরু হলে সেটিও Perfect conditional/ 3rd conditional হয়। তাই পরবর্তী clause এ - would/could/might + have + V3 + extension. ব্যবহৃত হয়।
