I can ret you can ret he can ret we can ret you can ret they can ret
V-ing form
I can be retting you can be retting he can be retting we can be retting you can be retting they can be retting
Perfect
I can have retted you can have retted he can have retted we can have retted you can have retted they can have retted
V-ing perfect
I can have been retting you can have been retting he can have been retting we can have been retting you can have been retting they can have been retting
Negation
Simple form
I cannot ret you cannot ret he cannot ret we cannot ret you cannot ret they cannot ret
V-ing form
I cannot be retting you cannot be retting he cannot be retting we cannot be retting you cannot be retting they cannot be retting
Perfect
I cannot have retted you cannot have retted he cannot have retted we cannot have retted you cannot have retted they cannot have retted
V-ing perfect
I cannot have been retting you cannot have been retting he cannot have been retting we cannot have been retting you cannot have been retting they cannot have been retting
Interrogative form
Simple form
can I ret? can you ret? can he ret? can we ret? can you ret? can they ret?
V-ing form
can I be retting? can you be retting? can he be retting? can we be retting? can you be retting? can they be retting?
Perfect
can I have retted? can you have retted? can he have retted? can we have retted? can you have retted? can they have retted?
V-ing perfect
can I have been retting? can you have been retting? can he have been retting? can we have been retting? can you have been retting? can they have been retting?
Interro-negative form
Simple form
can I not ret? can you not ret? can he not ret? can we not ret? can you not ret? can they not ret?
V-ing form
can I not be retting? can you not be retting? can he not be retting? can we not be retting? can you not be retting? can they not be retting?
Perfect
can I not have retted? can you not have retted? can he not have retted? can we not have retted? can you not have retted? can they not have retted?
V-ing perfect
can I not have been retting? can you not have been retting? can he not have been retting? can we not have been retting? can you not have been retting? can they not have been retting?