I can regret you can regret he can regret we can regret you can regret they can regret
V-ing form
I can be regreting you can be regreting he can be regreting we can be regreting you can be regreting they can be regreting
Perfect
I can have regreted you can have regreted he can have regreted we can have regreted you can have regreted they can have regreted
V-ing perfect
I can have been regreting you can have been regreting he can have been regreting we can have been regreting you can have been regreting they can have been regreting
Negation
Simple form
I cannot regret you cannot regret he cannot regret we cannot regret you cannot regret they cannot regret
V-ing form
I cannot be regreting you cannot be regreting he cannot be regreting we cannot be regreting you cannot be regreting they cannot be regreting
Perfect
I cannot have regreted you cannot have regreted he cannot have regreted we cannot have regreted you cannot have regreted they cannot have regreted
V-ing perfect
I cannot have been regreting you cannot have been regreting he cannot have been regreting we cannot have been regreting you cannot have been regreting they cannot have been regreting
Interrogative form
Simple form
can I regret? can you regret? can he regret? can we regret? can you regret? can they regret?
V-ing form
can I be regreting? can you be regreting? can he be regreting? can we be regreting? can you be regreting? can they be regreting?
Perfect
can I have regreted? can you have regreted? can he have regreted? can we have regreted? can you have regreted? can they have regreted?
V-ing perfect
can I have been regreting? can you have been regreting? can he have been regreting? can we have been regreting? can you have been regreting? can they have been regreting?
Interro-negative form
Simple form
can I not regret? can you not regret? can he not regret? can we not regret? can you not regret? can they not regret?
V-ing form
can I not be regreting? can you not be regreting? can he not be regreting? can we not be regreting? can you not be regreting? can they not be regreting?
Perfect
can I not have regreted? can you not have regreted? can he not have regreted? can we not have regreted? can you not have regreted? can they not have regreted?
V-ing perfect
can I not have been regreting? can you not have been regreting? can he not have been regreting? can we not have been regreting? can you not have been regreting? can they not have been regreting?