lose (one's) knack

Translations
потерять сноровку
He seems to have lost his knack for playing the guitar.
Кажется, он потерял сноровку в игре на гитаре.
Definitions
To lose one's knack means to lose the natural ability or skill to do something effectively or effortlessly, often after having previously been proficient at it.
Words
knack

noun
умение
lose

verb
терять