Standard Spanish grammar states that desideratives ("querer que"), directives ("aconsejar que"), purpose clauses ("para que"), causatives ("hacer que"), emotive-factives ("alegrarse de que"), negated epistemics ("no creer que"), dubitatives ("dudar que"), and modals ("ser posible que") embed subjunctive complement clauses. However, in spite of these classifications, some predicates exhibit a certain degree of mood variation. For instance, emotive-factives can take indicative complements (Crespo del Rio, 2014; Faulkner, 2021). Similar variability between the moods may also come about in negated epistemic (Bolinger, 1991), dubitative (Blake, 1981), and modal clauses (Deshors and Waltermire, 2019). When both moods are acceptable, the choice between the two conveys a difference in meaning (Kanwit and Geeslin, 2014, 2017). Corroborating this hypothesis are findings from Faulkner (2021), which demonstrated that the mood variation occurring in emotive-factive clauses relates to the INFORMATIVENESS of the embedded proposition; i.e., propositions that are addressee-new versus addressee-old. The objective of the current dissertation is to investigate the standardly subjunctive environments in which the use of the indicative may become acceptable. Two hundred and twenty-three native Spanish-speakers completed a 128-item Acceptability Judgment Task (AJT), pertaining to the use of each mood in eight traditionally subjunctive complements (desiderative, purpose, directive, causative, modal, dubitative, negated epistemic, and emotive-factive clauses). Participants rated separate instances of subjunctive and indicative based on the (un)informativeness of the complement proposition. Statistical analyses of the ratings revealed that subjunctive is always preferred over indicative in traditionally subjunctive environments. However, certain predicates were more receptive than others to taking indicative clauses. Whereas preference-based expressions (desideratives, directives, purpose clauses, causatives) require subjunctive complements, emotive-factives and verbs of uncertainty (negated epistemics, dubitatives, modals) may accept indicative if the speaker intends to add the affirmative or negated proposition to the common ground. The likelihood that this occurs increases when the proposition (affirmative or negated) is informative. Since this was the case regardless of the participants' countries of origin, said findings suggest that the Spanish mood system involves a split between two types of subjunctives, one that is required in preference-based contexts, and another that is default and can be replaced by the indicative. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]