Is there an English subjunctive?
Human beings – the only creatures who have language at their disposal to communicate – can talk about anything, including the past and the future. Typically when we talk about possible, desirable, or hypothetical situations in English we use modal verbs such as can/could, may/might, will/would, shall/should, and must. So we can say, for example, Peter may be in his room to express the possibility that he is there. Or we can say Peter must see his teacher to express an obligation on Peter’s part.
Another way of talking about possible, desirable, or hypothetical situations is by using what many grammars call a present subjunctive verb as in this example: It is necessary that Peter see his teacher. What makes the bolded verb special is that it does not have the third person singular –s ending that we find in declarative clauses that contain a present tense verb (e.g. Every day Peter sees his teacher).
Many languages have special verb forms for the subjunctive. For example in French we say Il est impératif que tu viennes (‘It is imperative that you come’) with the subjunctive verb form viennes, rather than Il est impératif que tu viens, which contains the indicative verb form viens.
So, is there an English subjunctive?
The question now arises whether it makes sense to say that English has subjunctive verb forms in the same way that French does. Many grammar books will tell you that it does. However, if you think about it you will realize that, unlike French, English has no special dedicated ‘present subjunctive endings’ on the verb in examples such as the one cited above. In fact, the form of the verb is simply the base form (sometimes also called the plain form), that we also find in sentences where infinitives are used (for example I went to see my cousin at the weekend). In view of this it makes more sense to speak of subjunctive clauses than of subjunctive verb forms. We can then say that the clause that Peter see his teacher in the example sentence is a subjunctive clause expressing an obligation on Peter’s part. Subjunctive clauses occur after words such as advisable, crucial, vital, necessary, imperative, etc., and are more common in American English than in British English. In British English it is also perfectly possible and acceptable to say It is necessary that Peter sees his teacher, which contains a declarative clause. Americans tend to find this odd.
What about ‘I wish he were…?’
What about the past subjunctive? Again, English has no special ‘past subjunctive verb endings’, so that we must conclude that English also has no past subjunctive verb forms. There’s one exception, though, and this is when we use were in an example like the following: I wish he were more helpful. This use of were is a relic of the past subjunctive. We now also frequently hear I wish he was more helpful.