I could recertify you could recertify he could recertify we could recertify you could recertify they could recertify
V-ing form
I could be recertifying you could be recertifying he could be recertifying we could be recertifying you could be recertifying they could be recertifying
Perfect
I could have recertified you could have recertified he could have recertified we could have recertified you could have recertified they could have recertified
V-ing perfect
I could have been recertifying you could have been recertifying he could have been recertifying we could have been recertifying you could have been recertifying they could have been recertifying
Negation
Simple form
I could not recertify you could not recertify he could not recertify we could not recertify you could not recertify they could not recertify
V-ing form
I could not be recertifying you could not be recertifying he could not be recertifying we could not be recertifying you could not be recertifying they could not be recertifying
Perfect
I could not have recertified you could not have recertified he could not have recertified we could not have recertified you could not have recertified they could not have recertified
V-ing perfect
I could not have been recertifying you could not have been recertifying he could not have been recertifying we could not have been recertifying you could not have been recertifying they could not have been recertifying
Interrogative form
Simple form
could I recertify? could you recertify? could he recertify? could we recertify? could you recertify? could they recertify?
V-ing form
could I be recertifying? could you be recertifying? could he be recertifying? could we be recertifying? could you be recertifying? could they be recertifying?
Perfect
could I have recertified? could you have recertified? could he have recertified? could we have recertified? could you have recertified? could they have recertified?
V-ing perfect
could I have been recertifying? could you have been recertifying? could he have been recertifying? could we have been recertifying? could you have been recertifying? could they have been recertifying?
Interro-negative form
Simple form
could I not recertify? could you not recertify? could he not recertify? could we not recertify? could you not recertify? could they not recertify?
V-ing form
could I not be recertifying? could you not be recertifying? could he not be recertifying? could we not be recertifying? could you not be recertifying? could they not be recertifying?
Perfect
could I not have recertified? could you not have recertified? could he not have recertified? could we not have recertified? could you not have recertified? could they not have recertified?
V-ing perfect
could I not have been recertifying? could you not have been recertifying? could he not have been recertifying? could we not have been recertifying? could you not have been recertifying? could they not have been recertifying?