Almost nobody seems to distinguish between the indicative and subjunctive mood of the verb to be anymore. Since I speak and write this way my internal alarm goes off when I read or hear the indicative mood of verbs in sentences or clauses that call for the subjunctive mood.
The subjunctive mood of the verb is required when the sentence or clause is conditional, or when a subordinate clause follows certain verbs in the main clause. A sentence or clause that starts with the word if is the most common form of a conditional sentence. A sentence or clause expressing a wish is also conditional.
The subjunctive form is also required in a clause following one of these verbs: ask, demand, determine, insist, move, order, pray, prefer, recommend, regret, request, require, suggest, and wish.
In English the subjunctive and indicative form of a verb are almost always the same, except for the present tense third person singular form of the that verb, and the verb to be.
The subjunctive form for the present tense third person drops the s or the es.
The subjunctive form of the verb to be is be in the present tense and were in the past tense, regardless of the subject.
Subordinate clause following one of the listed verbs:
Incorrect: My requirement is that everyone is on time.
Correct: My requirement is that everyone be on time.
(main clause contains a demand, verb in subordinate clause must be in subjunctive mood)
Incorrect: The captain asks that each officer on the scene files his own report.
Correct: The captain asks that each officer on the scene file his own report.
Conditional sentences or clauses:
Incorrect: I wish he was taller.
Correct: I wish he were taller.
Incorrect: If I was a rich man, yubby dibby dibby dibby dibby dybby dum …
Correct: If I were a rich man, yubby dibby dibby dibby dibby dybby dum …
There I’ve gotten* it off my chest! Use the subjunctive form of the verb when the sentence of clause requires it.
*["I’ve gotten” is American English, past participle form; British English is "I’ve got”, present tense; Old English is the same as modern American English and prefers “gotten;” Get it?]
Here is my offering of a little reward for suffering through this grammar lesson. Teyve uses the correct form of the verb: