The phrase "decisively affected" is grammatically correct and can be used in written English.
It means that something has been greatly influenced or impacted in a significant and final way. Example: The new policy decisively affected the company's profits, causing a significant decrease in their earnings.
Krieger Vasena was removed, but the Onganía administration was unable to agree on an alternative economic policy, and the Cordobazo decisively affected the political climate.
Furthermore, Italian architectural style was decisively affected by the fact that brick not stone was the most common building material and marble the most common decorative material.
The expansion of Rome into the Balkan Peninsula in the 3rd and 2nd centuries bce decisively affected the evolution of the Geto-Dacians.
It is true that Germany's opponents made serious tactical errors that probably delayed the war's end, but neither these errors nor the Allies' insistence on unconditional surrender decisively affected the prolonged agony of the endgame.
(Before Galois could finish his work, he died in a duel at age 21.) The arrival in Pisa of the German mathematician Bernhard Riemann in 1863 decisively affected the course of Betti's research.
There is a great esprit de corps about the World Service and a shared ethos among current and former staff based on the deeply held belief that we were all working to produce programmes for listeners, many of whom were deprived of the most basic information about the political, economic and social issues that decisively affected their lives.
But it isn't only Argentina whose players decisively affect Champions League games.
This suggests that dramatic examples of government dysfunction should perhaps be added to the short list of events that decisively affect presidential approval.
But it is rare that six-month presidencies decisively affect the Union's direction.That said, a truly erratic presidency of the sort that Mr Berlusconi promises to deliver could still do some real damage.
The U.S. is in the midst of the most important presidential election campaign since World War II, and if there has ever been a time when women voters had the opportunity to decisively affect the nation's future, it's now.
The Vietnam War and the 1973 Arab-Israeli War demonstrated, each in its own way, the limits of air power in the tactical role, and the 1982 Israeli invasion of Lebanon, in which the Israeli air force won a spectacular victory in the sky without decisively affecting the ground battle, provided even stronger proof.
