The phrase "assert forcefully" is correct and usable in written English.
It can be used when you want to emphasize the strength or intensity of a statement or belief being expressed.
Example: "During the debate, she chose to assert forcefully her position on climate change, leaving no room for doubt."
Alternatives: "state emphatically" or "declare strongly."
When asked how their respective triumphs affect each other's self-esteem, Mr Dunham asserts forcefully, "A rising tide lifts all boats.
"You told me it was over," he asserted forcefully.
He asserted forcefully that the time for bickering is over.
There is a danger, though, if not a likelihood, that the secret police and their corrupt allies in industry, or radical Islamists, will assert themselves forcefully.
Collaged areas of ground-up herbs create the sculptural texture of protean faces that sometimes sink beneath layers of paint, sometimes merge with their surroundings and sometimes assert themselves forcefully.
Re "Bush Planning to See Voters, and to Be Seen" (front page, Sept. 8): It's time for Presidents Gerald R. Ford and Jimmy Carter, as honorary chairmen of the bipartisan Commission on Presidential Debates, to assert themselves forcefully and publicly in favor of maintaining the traditional three-debate format.
The Grammy Awards show, historically, is a place where tradition asserts itself forcefully.
Although the government of President Mahmoud Ahmadinejad has asserted itself forcefully and demonstrations have more or less ceased, the political rift opened by the election remains.
One senior American official in Baghdad said the idea had been pushed by Dr. Allawi, who has asserted himself forcefully since being selected as prime minister in a process led by the United Nations earlier this month.
The Facebook executive Sheryl Sandberg published her book, "Lean In," urging women to shed fears and assert themselves more forcefully at work.
