Here are some ways "knack" is used:
* A special skill or talent: "He has a knack for making people laugh."
* An aptitude or ability to do something easily: "She has a knack for remembering names."
* A clever or skillful way of doing something: "He has a knack for finding bargains."
Essentially, "knack" implies that someone has a natural inclination or talent for something that others may find difficult. It's often used to describe someone who can do something well with ease, almost as if it comes naturally to them.