Element FORM/USE: INVERTED PAST PERFECT, IMAGINED PAST
SuperCat CLAUSES
SubCat conditional
Lexical Range N/A
Level C2
Cando Can use past perfect + inverted subject, and a modal verb + 'have' + '-ed' in the main clause to talk about imagined situations in the past.
Corrected Learner Example Had he been more experienced he would have known that these things always happen in this part of the world. (Sweden; C2 MASTERY; 2001; Swedish; Pass)

Had we known this fact we would have organised more activities within school hours. (Switzerland; C2 MASTERY; 2006; French; Pass)

Had we learnt from the mistakes of the past, we would have given up fighting each other a long time ago. (Russia; C2 MASTERY; 1998; Russian; Pass)

Had I known so many people from abroad were coming to visit our stand, I would have studied harder during my private lessons in the past. (Spain; C2 MASTERY; 1998; Spanish - European; Pass)

Had this file fallen into enemy hands, it might have had disastrous effects on the Western world. (Denmark; C2 MASTERY; 1993; Danish; Pass)

Had public transportation been an option I would have chosen that instead of my car. (Denmark; C2 MASTERY; 2010; Danish; Pass)
Uncorrected Learner Example
Comments Note on punctuation: many grammar books stress that when the 'if' clause precedes the main clause, it must use a comma. We cannot establish a consistent competency for this (and punctuation in general). It seems too idiosyncratic. L1 can be a skewing factor

Cambridge University Press