master
noun
a person with the ability or power to use, control, or dispose of something.
had been mastering
-
past perfect progressiveof master.past perfect progressive
Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The Agency was still smaller than its Russian counterpart, and its agents had to train hard to learn the techniques of spycraft—which Soviet operatives had been mastering for decades.
From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau
He had been reading up; he had been seeing distinguished confreres; he had been mastering the subject to the last dot, and was panting to begin.
From The Motormaniacs by Osbourne, Lloyd
