English verb conjugation
CAN RET

Regular verb: ret - retted - retted

Affirmation

Simple form	V-ing form
I can ret you can ret he can ret we can ret you can ret they can ret	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	V-ing 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	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	V-ing form
I cannot ret you cannot ret he cannot ret we cannot ret you cannot ret they cannot ret	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	V-ing 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	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	V-ing form
can I ret? can you ret? can he ret? can we ret? can you ret? can they ret?	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	V-ing 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?	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	V-ing 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?	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	V-ing 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?	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?