The phrase "an extraordinary command" is correct and usable in written English.
It can be used to describe a remarkable or impressive level of skill or authority in a particular area, such as language, technology, or leadership.
Example: "Her ability to navigate complex negotiations demonstrated an extraordinary command of diplomacy."
Alternatives: "an exceptional mastery" or "a remarkable proficiency".
There's no doubt that Shakespeare had an extraordinary command of the English language.
Lonergan shows an extraordinary command of tone and style, mixing comedy with drama of the weight of Miller or O'Neill.
It came in 67 when his adherent Gabinius, as tribune, secured him, against the opposition of all important men, an extraordinary command with unprecedented powers to deal with the pirates.
Jackendoff combines theoretical rigor with an extraordinary command over the rich complexities of language use and other social activities, yielding deep insights into the cognitive underpinnings of a sweeping range of human behaviors.
Ware has an extraordinary command of time and pacing: one bravura page depicts the florist and her husband dealing with her father's decline over several months, every panel a perfectly composed little square, the thought balloons doubling as after-the-fact narration, and the whole thing a tribute to the look of Frank King's old "Gasoline Alley" Sunday pages.
She sings Glitter and Be Gay with an extraordinary command of the higher registers for someone making her NYC debut.
But he showed extraordinary command of a late-moving fastball and had a keener understanding of hitters' swings, and after two starts at Class AAA in April 2011, Vogelsong quickly earned a promotion to the Giants.
In The Secular Scripture he turns again to the task of establishing a broad theoretical framework, bringing to bear his extraordinary command of the whole range of literature from antiquity to the present.
Marcum pitched superbly through seven innings, with extraordinary command.
Two of those came in the American League Championship Series against the Yankees, who were baffled by his extraordinary command and deceptive slider, his best pitch Saturday.
The Democrats will need their best hands on deck to prevail – and Clinton, with her extraordinary command of the details of healthcare, is unquestionably one of those hands.
