persistence in (something)

Translations
настойчивость в (чем-то)
His persistence in learning a new language eventually led to fluency.
Его настойчивость в изучении нового языка в конечном итоге привела к свободному владению.
Definitions
Persistence in something refers to the continued effort and determination to achieve a goal or maintain an activity despite challenges, obstacles, or setbacks. It implies a steadfast commitment to keep going and not give up.
Words
persistence

noun
настойчивость
in

preposition
в
something

pronoun
чём-либо