I can lead you can lead he can lead we can lead you can lead they can lead
V-ing form
I can be leading you can be leading he can be leading we can be leading you can be leading they can be leading
Perfect
I can have led you can have led he can have led we can have led you can have led they can have led
V-ing perfect
I can have been leading you can have been leading he can have been leading we can have been leading you can have been leading they can have been leading
Negation
Simple form
I cannot lead you cannot lead he cannot lead we cannot lead you cannot lead they cannot lead
V-ing form
I cannot be leading you cannot be leading he cannot be leading we cannot be leading you cannot be leading they cannot be leading
Perfect
I cannot have led you cannot have led he cannot have led we cannot have led you cannot have led they cannot have led
V-ing perfect
I cannot have been leading you cannot have been leading he cannot have been leading we cannot have been leading you cannot have been leading they cannot have been leading
Interrogative form
Simple form
can I lead? can you lead? can he lead? can we lead? can you lead? can they lead?
V-ing form
can I be leading? can you be leading? can he be leading? can we be leading? can you be leading? can they be leading?
Perfect
can I have led? can you have led? can he have led? can we have led? can you have led? can they have led?
V-ing perfect
can I have been leading? can you have been leading? can he have been leading? can we have been leading? can you have been leading? can they have been leading?
Interro-negative form
Simple form
can I not lead? can you not lead? can he not lead? can we not lead? can you not lead? can they not lead?
V-ing form
can I not be leading? can you not be leading? can he not be leading? can we not be leading? can you not be leading? can they not be leading?
Perfect
can I not have led? can you not have led? can he not have led? can we not have led? can you not have led? can they not have led?
V-ing perfect
can I not have been leading? can you not have been leading? can he not have been leading? can we not have been leading? can you not have been leading? can they not have been leading?