The subjunctive mood is a little-known, commonly used facet of the English language that has been on the decline, even in literary and academic circles, for several decades.

How is the subjunctive conjugated?

The subjunctive mood is conjugated as follows in English:

For the present tense, always use the infinitive*. This includes helping verbs such as be, do, and have. (if I be ; he says she be; hope he have; if he do)

For the past tense, always use the plural past tense. (if she were; wish they were)

For the future tense, conjugate as usual. (if she shall be; if they will have)

When should the subjunctive be used?

The primary use of the subjunctive in English is false conditions. That is, a subjunctive verb should be used in situations where the verb's action is assumed to not occur.

In the sentence ";I wish I were a dog," it is clear that the speaker is not a dog. Therefore she has used the subjunctive "were" instead of the ordinary "was"

The following words indicate a false condition and therefore a subjunctive verb: if, wish, hope. In some cases, the subjunctive may be used with think, but never with know.

(If it were so, . . .. I wish it were so. I hope it be so. I thought it were so / I thought it was so. I know it is so.)

In cases with if and think or if and say, use the subjunctive: "If I thought it were so. . .."

English also uses the subjunctive in cases of indirect quotation. That is, a subjunctive verb should be used when telling what someone said without a quote.

(I say he be nice. They say he do lawns. I tell you he have no money.)

Decline of the subjunctive

English has been losing its inflection for many centuries. It no longer has any fully conjugated verbs or fully declined nouns. The subjunctive seems the next likely casualty of this trend toward simplification.

The indirect-quotation use of the subjunctive has already been discarded by the vast majority of writers and speakers, and the false-condition use is used less and less in speech.