if+sub+past perfect,+sub+could/would/might+have+verb in pastparticple (v3) :if clause যদি past perfect হয় তবে পরবর্তী clause এ would, could.might+have এবং verb 3 হবে ।
i
Example:-
-if we had knowr that yot were there, we would haue writleryo.
-what would have happende,if the bridge had broker.
