verb in the imperfect of the potential mood, the conjunctive form of the imperfect tense must be employed; as, “If he were here, we should rejoice together;” “She might go, were she so disposed.”  But when there is no reference to present or future time, and the verb is neither followed nor preceded by another in the potential imperfect, the indicative form of the imperfect tense must be used; as, “If he was ill, he did not make it known;” “Whether he was absent or present, is a matter of no consequence.”  The general rule for using the conjunctive form of the verb, is presented on page 145.  See, also, page 135.

The perfect, pluperfect, and first future tenses of the subjunctive mood, are conjugated in a manner similar to the correspondent tenses of the indicative.  The second future is conjugated thus: 

Second Fut.  T. Sing.  If I shall have been, if thou shalt have been, if he shall. &c Plur.  If we shall have been, if you shall have been, if they, &c.

IMPERATIVE MOOD. 
Pres.  Tense.
Sing.  Be, or be thou, or do thou be.
Plur.  Be, or be ye or you, or do ye or you be.

POTENTIAL MOOD. 
Pres.  Tense
Sing.  I may, can, or must be, thou mayst, canst, or must be,
                                  he may, can, or must be.
Plur.  We may, can, or must be, ye or you may, can, or must be,
                                  they may, can, or must be. 
Imperf.  Tense.
Sing.  I might, could, would, or should be, thou mightest, &c.
Plur.  We might, could, would, or should be, you might, &c.

Perf.  Tense Sing.  I may, can, or must have been, thou mayst, canst, &c. Plur.  We may, can, or must have been, you may, can, or must be, &c.

Pluper.  Tense. Sing.  I might, could, would, or should have been, thou, &c. Plur.  We might, could, would, or should have been, you, &c.

INFINITIVE MOOD. 
Pres.  Tense.  To be.  Perf.  Tense.  To have been.

PARTICIPLES. 
Pres.  Being.  Perf.  Been.  Compound, Having been.

This verb to be, though very irregular in its conjugation, is by far the most important verb in our language, for it is more frequently used than any other; many rules of syntax depend on constructions associated with it, and, without its aid, no passive verb can be conjugated.  You ought, therefore, to make yourself perfectly familiar with all its changes, before you proceed any farther.

* * * * *

II.  PASSIVE VERBS.

The cases of nouns are a fruitful theme for investigation and discussion.  In the progress of these lectures, this subject has frequently engaged our attention; and, now, in introducing to your notice the passive verb, it will, perhaps, be found both interesting and profitable to present one more view of the nominative case.