GMAT Verbal Section | Ultimate GMAT Grammar Book: Exercise 30: Using Modals

Hi,

I need some clarifications on below questions in Exercise 30, using modals.

Q2. Had Jonathon not fallen down the stairs, he ________________ be playing in the game tonight.
This is a case of Unreal Past Condition. The formula is Had + subject + Past Perfect + would/could/might + have + past participle.
In the 1st clause of the sentence,Had not fallen is past perfect, which matches with the formula. So the 2nd clause must havecould/would + have + been playing instead of could/would be
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