A static type, called “dynamic”, is introduced into a statically bound programming language. An expression or subexpression that is defined as a static type called “dynamic” in the source code of a program written in the statically bound programming language, is bound based on its runtime type instead of on its compile time type. Binding can be performed based on a mixture of compile time and runtime types that are based on the specification of types of expressions in source code. This type of binding is called hybrid binding. Operations are bound using the runtime type of constituent expressions (i.e., the runtime type of a receiver, an argument, or an operand) typed as dynamic and the compile time type of static constituents. If any constituent expression of an operation is dynamic, binding occurs at runtime instead of at compile time.