https://www.scribbr.com/verbs/subjunctive-mood/

The subjunctive mood is a verb form used to refer to a hypothetical scenario or to express a wish, suggestion, or command.

The subjunctive is one of three grammatical moods in English, along with the indicative mood and the imperative mood.

There are two types of subjunctive verb forms:

– Verbs in the present subjunctive take the infinitive form (e.g., “be”).
ex: He saw [a person put bread] on the table.

– while verbs in the past subjunctive are identical to their simple past forms (e.g., “ran”).
ex: I wish [I had rich parents].

The present subjunctive

The present subjunctive is typically used to refer to future actions or situations. Sentences in the present subjunctive mood have two clauses:

A main clause that contains either an indicative verb (e.g., “Kahn recommended”) or a phrase that starts with “it is” and contains an adjective (e.g., “It is important”)

A subordinate clause in the subjunctive mood (usually beginning with the conjunction “that”)
Verbs in the present subjunctive do not follow subject-verb agreement. Instead, they take the infinitive form for all persons (e.g., “be,” “eat,” “sing”).

Examples:

• The doctor suggested that she rest.
• I propose that we take a short break.
• It is advisable that the CEO resign.
• It’s vital that we not miss our flight.
• The artist asks that you not touch the paintings.

The past subjunctive

The past subjunctive is typically used to refer to past or present actions or situations. Sentences in the past subjunctive mood contain two clauses:

A main clause in the indicative mood (often containing the verb “wish”)

A subordinate clause in the subjunctive mood (usually beginning with “that,” “if” or “as if”).

The past subjunctive form of the verb “be” is “were,” regardless of the subject (e.g., “I were,” “he were,” “she were”). All other verbs in the past subjunctive form are identical to their simple past tense forms (e.g., “I won”).

Examples:

• Karla acts as if she were famous.
• I wish I lived in New York.

When the past subjunctive form is used in an “if” clause, the main clause usually contains a modal verb (normally “would,” but sometimes “should,” “might,” or “could”).