Had it not been for his guidance, we ___ failed.

• Complete Sentence: Had it not been for his guidance, we would have failed.
- Bangla Meaning: যদি তার নির্দেশনা না থাকত, তাহলে আমরা ব্যর্থ হতাম।

• প্রশ্নে উল্লিখিত Sentence টি একটি Third Conditional sentence.
- একটি Conditional sentence-এ দু’টি clause থাকে: subordinate clause এবং principal clause।
- Subordinate clause -টি শর্ত বোঝায় এবং principal clause-টি ফলাফল বোঝায়।

• Third conditional -এর নিয়মানুযায়ী:
- If clause (শর্তযুক্ত অংশে) -এ যদি (had + V3) হয়, তবে পরবর্তী clause -এ would/could/might + have + V3 + extension হয়।
- If না থাকলে Condition part টি 'Had' দ্বারা শুরু হয়।

• Structure: Had + Subject + V3 + Subject + would/could/might + have + V3 + Ext.

• More Examples:
1. Had I been rich, I would have helped her.
2. Had I been in your situation, I would have accepted the offer.

Source: Advanced Learner's Communicative English Grammar and Composition by Chowdhury and Hossain.