the rule of using expressing regret
What man does not remember with regret the first time he read Robinson Crusoe?
Never any prince expressed a more lively regret for the loss of a servant.
regret = pain of mind on account of something done or experienced in the past, with a wish that it had been different; a looking back with dissatisfaction or with longing; grief; sorrow; especially, a mourning on account of the loss of some joy, advantage, or satisfaction
We regret to inform you that your husband Capt John E Jones, SSN 555-55-5555 was killed.
We regret to have to announce the death of your father.
Please accept my regrets.
regret feeling sorrow, grief (due to loss, loss)
We regret to inform you that we cannot process your order.
We regret that we cannot accept your invitation.
I regret that I cannot come on Monday.
regret = expresses chagrin speaker about impossibility do smth. specifically. impossibility take invitation
We regret to inform you that your position has been eliminated.
to regret deeply, very much (grieve)
I regret having to leave so early.
Everyone regretted his being dismissed.
regret = be sorry
He did not come but sent his regrets.
regret = excuse
I don't regret moving to York.
regret = repent (be sorry)
It is to be regretted that he died with his most cherished hopes unfullfilled.
He died regretted by all.