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