Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I can regret regret you can regret regret he can regret regret we can regret regret you can regret regret they can regret regret
V-ing form
I can be regret regreting you can be regret regreting he can be regret regreting we can be regret regreting you can be regret regreting they can be regret regreting
Perfect
I can have regret regreted you can have regret regreted he can have regret regreted we can have regret regreted you can have regret regreted they can have regret regreted
V-ing perfect
I can have been regret regreting you can have been regret regreting he can have been regret regreting we can have been regret regreting you can have been regret regreting they can have been regret regreting
Negation
Simple form
I cannot regret regret you cannot regret regret he cannot regret regret we cannot regret regret you cannot regret regret they cannot regret regret
V-ing form
I cannot be regret regreting you cannot be regret regreting he cannot be regret regreting we cannot be regret regreting you cannot be regret regreting they cannot be regret regreting
Perfect
I cannot have regret regreted you cannot have regret regreted he cannot have regret regreted we cannot have regret regreted you cannot have regret regreted they cannot have regret regreted
V-ing perfect
I cannot have been regret regreting you cannot have been regret regreting he cannot have been regret regreting we cannot have been regret regreting you cannot have been regret regreting they cannot have been regret regreting
Interrogative form
Simple form
can I regret regret? can you regret regret? can he regret regret? can we regret regret? can you regret regret? can they regret regret?
V-ing form
can I be regret regreting? can you be regret regreting? can he be regret regreting? can we be regret regreting? can you be regret regreting? can they be regret regreting?
Perfect
can I have regret regreted? can you have regret regreted? can he have regret regreted? can we have regret regreted? can you have regret regreted? can they have regret regreted?
V-ing perfect
can I have been regret regreting? can you have been regret regreting? can he have been regret regreting? can we have been regret regreting? can you have been regret regreting? can they have been regret regreting?
Interro-negative form
Simple form
can I not regret regret? can you not regret regret? can he not regret regret? can we not regret regret? can you not regret regret? can they not regret regret?
V-ing form
can I not be regret regreting? can you not be regret regreting? can he not be regret regreting? can we not be regret regreting? can you not be regret regreting? can they not be regret regreting?
Perfect
can I not have regret regreted? can you not have regret regreted? can he not have regret regreted? can we not have regret regreted? can you not have regret regreted? can they not have regret regreted?
V-ing perfect
can I not have been regret regreting? can you not have been regret regreting? can he not have been regret regreting? can we not have been regret regreting? can you not have been regret regreting? can they not have been regret regreting?