General truths and present facts should be expressed in the present tense, whatever the tense of the principal verb:  [He believed that truth is unchangeable.  Who did you say is president of your society?].

The perfect infinitive is used to denote action completed at the time of the main verb:  [I am sorry to have wounded you].

+63.  Mode.+—­A statement may be regarded as the expression of a fact, of a doubt or supposition, or of a command.  The power of the verb to show how an action should be regarded is called mode (mood).  In our language there is but a slight change of form for this purpose.  The distinction of mode which we must make is a distinction that has regard to the thought or attitude of mind of the speaker rather than to the form of the verb.

The indicative mode is used to state a fact or to ask questions of fact:  [I shall write a letter.  Shall I write a letter?].

The subjunctive mode indicates uncertainty, unreality, and some forms of condition:  [If she were here, I should be glad].

The imperative mode expresses a command or entreaty:  [Come here].

+64.  The Subjunctive Mode.+—­The subjunctive is disappearing from colloquial speech, and the indicative form is used almost entirely.

The verb to be has the following indicative and subjunctive forms in the present and preterite:—­

IND.        SUBJ.                   IND.         SUBJ.
{ I am        I be                { I was       I were
{ Thou art    Thou be             { Thou wast   Thou were
PRESENT { He is       He be    PRETERITE  { He was      He were
{ We are      We be               { We were     We were
{ You are     You be              { You were    You were
{ They are    They be             { They were   They were

In other verbs the indicative and subjunctive forms are the same, except that the second and third persons singular subjunctive have no personal endings.

INDICATIVE               Thou learnest            He learns
SUBJUNCTIVE              Thou learn               He learn

The subjunctive idea is sometimes expressed by verb phrases, containing the auxiliary verbs may (might), would, or should. May, would, and should are not, however, always subjunctive.  In “I may go” (may = am allowed to), may is indicative.  In “you should go” (= ought to), should is indicative.

The subjunctive mode is used most frequently to express:—­

1.  A wish:  [The Lord be with you].

2.  A condition regarded as doubtful:  [If it be true, what shall we think?], or a condition regarded as untrue:  [If I were you, I should go].  When condition is expressed by the subjunctive without if, the verb precedes the subject:  [Were my brother here, he could go with me].

3.  A purpose:  [He studies that he may learn].