Singular.                    Plural.
1.  If I love,                   1.  If we love,
2.  If thou love,                2.  If ye or you love,
3.  If he love.                  3.  If they love.

Look again at the conjugation in the indicative present, and you will observe, that the form of the verb differs from this form in the subjunctive.  The verb in the present tense of this mood, does not vary its termination on account of number or person.  This is called the conjunctive form of the verb; but sometimes the verb in the subjunctive mood, present tense, is conjugated in the same manner as it is in the indicative, with this exception, if, though, unless, or some other conjunction, is prefixed; as,

Indicative form.

Singular.                      Plural.
1.  If I love,                   1.  If we love,
2.  If thou lovest,              2.  If ye or you love,
3.  If he loves,                 3.  If they love.

The following general rule will direct you when to use the conjunctive form of the verb, and when the indicative.  When a verb in the subjunctive mood, present tense, has a future signification, or a reference to future time, the conjunctive form should be used; as, “If thou prosper, thou shouldst be thankful;” “He will maintain his principles, though he lose his estate;” that is, If thou shalt or shouldst prosper; though he shall or should lose, &c.  But when a verb in the subjunctive mood, present tense, has no reference to future time, the indicative form ought to be used; as, “Unless he means what he says, he is doubly faithless.”  By this you perceive, that when a verb in the present tense of the subjunctive mood, has a future signification, an auxiliary is always understood before it, for which reason, in this construction, the termination of the principal verb never varies; us, “He will not become eminent, unless he exert himself;” that is, unless he shall exert, or should exert himself.  This tense of the subjunctive mood ought to be called the elliptical future.

The imperfect, the perfect, the pluperfect, and the first future tenses of this mood, are conjugated, in every respect, like the same tenses of the indicative, with this exception; in the subjunctive mood, a conjunction implying doubt, &c. is prefixed to the verb.  In the second future tense of this mood, the verb is conjugated thus: 

Second Future Tense.

   Singular. Plural.

1.  If I shall have loved, 1.  If we shall have loved, 2.  If thou shalt have loved, 2.  If you shall have loved, 3.  If he shall have loved. 3.  If they shall have loved.

Look at the same tense in the indicative mood, and you will readily perceive the distinction between the two conjugations.