About the use of subjunctive

The following is a mini-tutorial on the use of the Subjunctive. After you have studied the tutorial, complete the associated exercises.
Modern Form
The subjunctive in Modern English is easily distinguished in a great variety of contexts where the sense is past tense, but the form of the subjunctive verb required is present: "It was required that we go to the back of the line". Were it not the subjunctive, the form of "to go" for something in the past would be went. Compare with the indicative, "Everyone knows that we went to the back of the line".
FORM
Use the simple form of the verb. The simple form is the infinitive without the "to." The simple form of the verb "to go" is "go." The Subjunctive is only noticeable in certain forms and tenses.
USE
The Subjunctive is used to emphasize urgency or importance. It is used after certain expressions (see below).
Examples:
I suggest that he study.
Is it essential that we be there?
Don recommended that you join the committee.
NOTICE
The Subjunctive is only noticeable in certain forms and tenses. In the examples below, the Subjunctive is not noticeable in the you-form of the verb, but it is noticeable in the he-form of the verb.
Examples:
You try to study often. you-form of "try"
It is important that you try to study often. Subjunctive form of "try" looks the same.
He tries to study often. he-form of "try"
It is important that he try to study often. Subjunctive form of "try" is noticeable here.