The subjunctive is a grammatical mood. Many languages use subjunctive verb forms to indicate varying degrees of uncertainty and unreality.
It is sometimes difficult to distinguish subjunctive in English because the verb form is identical to forms in the indicative mood. In some other languages, like Spanish, the subjunctive verb forms are visually and functionally distinct from the indicative forms. The following is a classic example of the subjunctive mood in English.
“I wish I were a movie star.” (Subjunctive)
(“I wish I was …” is incorrect as it does not use the subjunctive verb form, which looks the same as, but is functionally different from, the past simple for both second person singular and third person plural.)
Here are some more subjunctive examples:
“Maybe he went to the game.”
“I wish this car went faster.”
“If I were you, I would read your homework.”