The phrase "with his fluency" is correct and usable in written English.
It can be used when discussing someone's ability to speak or write a language smoothly and effortlessly.
Example: "He impressed everyone with his fluency in Spanish during the presentation."
Alternatives: "due to his fluency" or "thanks to his fluency."
He entrances people here with his fluency in Japanese.
That decision, along with his fluency in German, helped him establish an extraordinary level of trust with many of the prisoners.
With his fluency in Morse code, the boy was able to help rescue a family in Key Largo, Fla., during a hurricane in 1926.
When writing of Flaubert's most famous novel ("a large fact of our cultural history.... Dickens and Victor Hugo beware") he contrasts the writer's agonizingly slow, perfectionist progress with his fluency in letters.
One can only also be impressed with his fluency in the Spanish language (a shout out to my wife who hails from Cuba).
"I've tried to have free votes, where possible, on these sort of issues," Cameron began with his usual fluency.
This time, he has turned to a James Baldwin novel from 1974, "If Beale Street Could Talk," adapting it for the screen and directing with his customary fluency and care.
In the wake of controversy over his call to repeal anti-discrimination laws, Nigel Farage handled himself with his usual fluency on Radio 4's Today programme.
The problem with his striking fluency and his mastery of detail was that it appeared to lead him into believing that he could tackle almost any problem or event without much by way of detailed preparation.
Though Mr. Hijuelos writes with his usual fluency and poise, this book does not have the satisfying narrative arc of "Mr. Ives' Christmas 199595), a Dickensian tale of a modern-day Job and his struggle to hold onto his "small, if imperfect, spiritual gift," or the fecund inventiveness of "Mambo Kings".
Spielberg directs with his customary fluency: he sends the camera (Janusz Kaminski is the cinematographer) sweeping across an enormous marble-and-glass set filled with high-end stores and consumerist fetishes, and he captures the humming lights and glaring emptiness of the late-night lounges, the exhausting boredom of the functional public place.
