The phrase "I have to regretfully" is grammatically correct and can be used in written English.
It is typically used to express regret or disappointment about something that one must do or say. An example could be: "I have to regretfully inform you that your application for the job has been rejected."
The announcement was made by the show's publicists, who said only that Mr. Strathairn "had to regretfully leave the production prior to rehearsals beginning".
Someone has to, regretfully so".
Regretfully, I had to leave the Tempest Freerunning Academy in Chatsworth, California.
And I regretfully have to admit, the past several weeks have been good, just good.
That afternoon my friends whisk me into the countryside, to an impressive salt-mine-turned-underground-cathedral in the town of Zipaquirá, and we spend another couple of days roaming the Zona Cafetera (coffee country) in the highlands west of the capital before I regretfully have to catch my plane home.
Despite several follow-up e-mails, LaBolt never got back to me, so I regretfully have to state the following: It appears that Obama, like George W. Bush, so rigidly supports Israeli policies that he is willing to trust ideologically driven right-wing think tanks more than he does reputable human rights groups.
Lake, who is now head of the UN Children's Fund, Unicef, said last week: "While holding the position of executive director of Unicef, whose humanitarian mission depends on its non-political character, I have had to decline, often regretfully, to speak publicly about events in my previous career as a government official.
I reviewed a novel recently that I had regretfully to give a thumbs-down, though it was terribly well intended; its heart was in the right place.
"Today I have regretfully been forced to accept the resignations of 1,541 of the finest public servants it has ever been my privilege to know," Mr. Frye's Nixon intones on the album.
The topic I have chosen to discuss is regretfully as controversial to some as it is fascinating to me, but as A. T. Still, the founder of Ostepathic Medicine, once said, "I have no desire to be a cat, which walks so lightly that it never creates a disturbance".
I did it regretfully, I don't normally have to do that, in the end it dragged on and on".
