The phrase "able to exercise a" is correct and usable in written English.
It can be used when discussing someone's capacity or capability to perform a specific action or function.
Example: "The committee is able to exercise a significant influence on policy decisions."
Alternatives: "capable of exercising a" or "in a position to exercise a".
"Under existing law, the investment adviser is able to exercise a pervasive influence over the board".
Turkey is an asset to its Nato partners when it is able to exercise a leadership role.
Still, some, like Larry Sauer, a board member for District 3, on the Upper West Side, said they had been able to exercise a kind of moral persuasion.
In addition to performance-enhancing effects during a race, this can also mean that a trainer will be able to exercise a horse more regularly and strenuously beforehand.
Now that Godard had his own studio, he was intimate with his tools and was able to exercise a craftsmanlike virtuosity in every aspect of his art.
With Franken in office, Democrats in the Senate (supported by the chamber's two independents) would be able to exercise a filibuster-proof 60 40 majority.
Should Verizon manage to open its local telephone markets within the next five years, it would be able to exercise an option to control 80percentt of Genuity.
Able to exercise an escape clause in his contract this summer, the player the Detroit Pistons have tethered their image to can up and leave if he wants.
Persimmon's strong run since 2011 will mean that Farley, who retired in April 2013, will be able to exercise an allotment of 966,400 shares on 31 December under a deal agreed by Persimmon's board in 2012.
Under the new rules the executor may not be able to exercise disclaimers or exercise a spouse's right to assume ownership of an inherited account and name new beneficiaries.
