A more thorough explanation:

Springing executory interest

A type of future interest that becomes effective only when a specific event occurs, and it follows an interest that the grantor held.

For example, a grantor may convey a piece of property to their child, but only when the child graduates from college. Until the child graduates, the grantor retains ownership of the property. Once the child graduates, the ownership of the property "springs" from the grantor to the child, creating an executory interest.

Another example is a grantor conveying a piece of property to a charity, but only if the charity uses the property for a specific purpose, such as building a community center. If the charity fails to use the property for the specified purpose, the ownership of the property "springs" back to the grantor or to another designated party.

Springing executory interests are future interests that "spring" into effect only when a specific event occurs. These interests follow an interest that the grantor held, and they can be used to ensure that property is used for a specific purpose or that ownership is transferred only when certain conditions are met. The examples illustrate how a springing executory interest works in practice, showing how ownership of property can be transferred or retained based on specific conditions.