The subjunctive in English plays a much less important role that in many other languages and rules regarding its use are not widely understood. In English, a verb must be in the subjunctive form when it presents a condition that is doubtful or contrary to fact. Clauses that begin with the word “if” are most often introducing a verb that must be in the subjunctive mood. An example of this would be, “if I were rich…” You will often hear such a construction using “was” instead of “were.” “If I was rich” is incorrect and should not be used.
Another instance when the subjunctive is needed is the expression of a wish, as in “Don’t you wish you were young again?” As you can see, “were” sounds much better to the even slightly educated ear than “was.” Listen to “Don’t you wish you was young again?” The correct form, were, is more pleasing to hear and gives most people a strong clue of the needed word.
In addition to the above example, where a wish is expressed, there are two other categories that require the subjunctive. These are when something is doubtful or when it is contrary to fact. An example of these would be, “I had hoped you were honest.” This use indicates that the speaker doubts that you are honest or expresses the speaker’s knowledge or belief that you are not honest. The exact meaning would depend upon the situation or context in which it is being used.