If you had read the book I mentioned, ______.

বাক্যটি 3rd Conditional হবে, কারণ If + Sub + had + PP আছে। (আর I mentioned মূলত Book এর Adjective Clause হিসেবে ব্যবহৃত। এটা Conditional Sentence এর অংশ নয়।)

তাই ২য় অংশটি হবে- Sub + would/could/might + have + Past Participle of the verb

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Structure of conditional sentence:
• Zero Conditional = If + Present + Present (shows scientific and general truth)
• 1st Conditional = If + Present + Future
• 2nd Conditional = If + Past Simple + Future in Past (S + would/might/could + Base Form of the Verb)
• 3rd Conditional = If + Past Perfect (had +V3) + Perfect Modal (S + would have/could have/might have + V3)