Possessives

• reaction: The resulting ' knee jerk ' emotional reaction has the potential to use a great deal your personal energy.

Modifies a noun

• reaction: No need for the knee jerk reaction week's prior.

• response: The shift system is the result of knee jerk response to the European law.

• way: Before I get accused of reacting in a knee jerk way to recent events.

• action: The knee jerk action is well-known, but there are many others.