The subjunctive is actually a very diverse tool with the world of grammar. A word in this tense can be used to express such wide ranging concepts as possibility, necessity, emotion, and judgment. It can even be utilized as part of subordinate clauses to indicate commands. In addition, a subjunctive can be an important part of the process of conveying a statement that presents as fact an idea that is contrary to current understandings.
In modern English, using the subjunctive often comes into play in order to more fully articulate not only the action, but also tell something about the nature of the action. For example, it is relatively easy to make the non-subjunctive statement of “We went to the store for food.” However, the simple statement takes on additional meaning and power when the action is restated using a subjunctive tense. “We were required to go to the store and buy food,” provides the understanding of necessity as associated with the task.
There are several categories of groupings of subjunctives. The present and past subjunctive deal with forms. For example, “I own” is a present subjunctive that implies a current state. “I owned” is an example of a past subjunctive that indicates that the form has changed in some manner from a former state.
The pluperfect subjunctive is sometimes referred to as the past perfect subjunctive, and may be used to indicate past tense in a fuller form. It is not unusual for this type to include the use of the word “had” as part of the verbal structure, such as “if I had known” or “if I had been aware.” The verb helps to qualify whatever information follows.
A third noteworthy form is the future subjunctive. Generally meant to quality some future action, this type of verb proposes a possibility. “If I were to change” is an excellent example of this, as it indicates that making some sort of change will impact a future set of circumstances.