Cách sử dụng
"Knock on wood" is an expression that people usually use when they want to avoid bad luck or jinxing something. If you say something good or optimistic, you would knock on a piece of wood (or anything that resembles wood) as you say the phrase to hopefully prevent anything bad from happening. It is a common saying in English speaking countries, and people use it in various situations, such as when discussing health, job prospects, or a sports team's success.