The phrase "a diligent study" is correct and usable in written English.
It can be used to describe a thorough and careful examination or analysis of a subject or topic.
Example: "The researchers conducted a diligent study to understand the effects of climate change on local ecosystems."
Alternatives: "a thorough investigation" or "a careful analysis."
Theodore Hagen of The Review and the World helpfully counseled that Gottschalk, given his "natural capacity for technics," might, pending a few years' diligent study of Bach and Clementi, master some of the simpler classics as well as certain minor compositions by Chopin and Weber.
The statistics come from The Management by Michael Grant and Rob Robertson, an insightful and diligent study of why Scots make such successful managers, and it is their hold on the Premier League that is revealing.
It's easy to think of the greatest investors of all time and imagine people who, either through some sort of gift of birth or years upon years of diligent study, had a complete understanding of the economy and the stock market.
Something resembling a caste something would remain where diligent study and hard work go unrewarded.
Like many volunteers, I often felt overwhelmed and ineffective; it took two years of diligent study just to gain a decent facility with the Chinese language.
As a college student, now an Orthodox Jew, she was drawn to Christianity through diligent study, constant questioning and careful, nearly obsessive attention to spiritual teachings.
Posey showed diligent study habits at Florida State, where he enrolled after a stellar high school career in Georgia.
Rather, it's the testimony of a man of faith, who has never let his lifetime of diligent study interfere with his worship of these authors.
His diligent study of music was combined with out-of-body experiences and a fascination with the vernacular and the exotic.
Through years of diligent study they have mastered this country's difficult language.
