I can defend you can defend she can defend we can defend you can defend they can defend
V-ing form
I can be defending you can be defending she can be defending we can be defending you can be defending they can be defending
Perfect
I can have defended you can have defended she can have defended we can have defended you can have defended they can have defended
V-ing perfect
I can have been defending you can have been defending she can have been defending we can have been defending you can have been defending they can have been defending
Negation
Simple form
I cannot defend you cannot defend she cannot defend we cannot defend you cannot defend they cannot defend
V-ing form
I cannot be defending you cannot be defending she cannot be defending we cannot be defending you cannot be defending they cannot be defending
Perfect
I cannot have defended you cannot have defended she cannot have defended we cannot have defended you cannot have defended they cannot have defended
V-ing perfect
I cannot have been defending you cannot have been defending she cannot have been defending we cannot have been defending you cannot have been defending they cannot have been defending
Interrogative form
Simple form
can I defend? can you defend? can she defend? can we defend? can you defend? can they defend?
V-ing form
can I be defending? can you be defending? can she be defending? can we be defending? can you be defending? can they be defending?
Perfect
can I have defended? can you have defended? can she have defended? can we have defended? can you have defended? can they have defended?
V-ing perfect
can I have been defending? can you have been defending? can she have been defending? can we have been defending? can you have been defending? can they have been defending?
Interro-negative form
Simple form
can I not defend? can you not defend? can she not defend? can we not defend? can you not defend? can they not defend?
V-ing form
can I not be defending? can you not be defending? can she not be defending? can we not be defending? can you not be defending? can they not be defending?
Perfect
can I not have defended? can you not have defended? can she not have defended? can we not have defended? can you not have defended? can they not have defended?
V-ing perfect
can I not have been defending? can you not have been defending? can she not have been defending? can we not have been defending? can you not have been defending? can they not have been defending?