ABSTRACT
The subjunctive is expressed by a particular set of forms which verbs can typically take only in subordinate clauses (but see 11.4.4 for an exception). Verb forms that are not those of the subjunctive (e.g. the simple present, imperfect, simple past, compound past, and so on) are traditionally called the indicative. This distinction is used in this chapter for expository purposes. The selection of the subjunctive in a subordinate clause (rather than the normal indicative) is always determined by the nature of the clause on which it is dependent.
It should be noted that in many cases there is no choice about whether to use the subjunctive or indicative: certain types of main clause ALWAYS select the subjunctive in a dependent subordinate clause; others ALWAYS select the indicative. However, some main clause constructions are ambiguous, and allow the verb in a dependent subordinate clause to be either subjunctive or indicative: the choice of one or the other produces different meanings.
