The phrase "an assertive presence" is correct and usable in written English.
It can be used to describe someone who has a strong, confident, and commanding demeanor in a particular situation.
Example: "During the meeting, her assertive presence helped steer the discussion towards a productive outcome."
Alternatives: "a commanding presence" or "a confident demeanor."
Although the individual paintings are small, the group has an assertive presence.
Darius Vassell, once more an assertive presence, fought to reach a pass from his fellow substitute Owen Hargreaves.
That Ms. Spero was deliberately, defiantly out of step with the New York School gives these canvases an assertive presence, even if they are not her best works.
The building, hemmed in by dark plantings but cozy under its blanket of snow, is at once a shelter from the elements and an assertive presence in the landscape.
Clarke's 251 off 342 balls overnight against India provided confirmation not just of fine form and an ability to respond positively to pressure, but of a more assertive presence at the crease.
Mr. Hayes was a less assertive presence, but he locked in well with Mr. Raymer, a smartly physical drummer.
Unlike Bremer, who was a ubiquitous, assertive presence in Iraq during his fourteen months as C.P.A. administrator, Negroponte has been unobtrusive, allowing Allawi to become the public face of the occupation.
Despite its huge energy interests in the Middle East, China has been reluctant to get deeply involved in the complicated diplomacy of the region, and the government has declined to heed the calls of some nationalists for a more assertive presence.
A more assertive presence in the East China Sea? Previews of the answers Clinton might give on the campaign trail suggest a leader who is more hawkish than Obama – possibly much more hawkish, foreign-policy watchers say – but who may be guided by a preference for alliance-based negotiations of the kind that informed her husband's presidency.
Tall, slender and boyishly handsome, with an explosive intelligence and assertive presence, she made sexual gratification an evangelical pursuit.
Hiroki Kuroda, the Yankees' solid veteran, and Yu Darvish, the Texas Rangers' rookie sensation with baffling stuff and an assertive mound presence, became the seventh set of Japanese starters to face each other in the major leagues.
