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 can't regret you can't regret he can't regret we can't regret you can't regret they can't regret
V-ing form
I can't be regreting you can't be regreting he can't be regreting we can't be regreting you can't be regreting they can't be regreting
Perfect
I can't have regreted you can't have regreted he can't have regreted we can't have regreted you can't have regreted they can't have regreted
V-ing perfect
I can't have been regreting you can't have been regreting he can't have been regreting we can't have been regreting you can't have been regreting they can't 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't I regret? can't you regret? can't he regret? can't we regret? can't you regret? can't they regret?
V-ing form
can't I be regreting? can't you be regreting? can't he be regreting? can't we be regreting? can't you be regreting? can't they be regreting?
Perfect
can't I have regreted? can't you have regreted? can't he have regreted? can't we have regreted? can't you have regreted? can't they have regreted?
V-ing perfect
can't I have been regreting? can't you have been regreting? can't he have been regreting? can't we have been regreting? can't you have been regreting? can't they have been regreting?