What does command structure mean?
A command structure is called the imperative form. In English, it is formed by the a verb and an optional object. For example, “Sit down” is a command, it is a very but there isn’t an object. Some verbs need objects, (transitive) and some verbs don’t require an object (intransitive). Any verb or verb-object combination that is understood as a single command can be used as an embedded command.