One decision question, not a conjugation drill
English speakers meet the Spanish subjunctive as a chart of endings. The chart matters later. The first useful question is which mood the clause needs at all. The RAE Libro de estilo section on indicativo o subjuntivo states that mood choice is conditioned by many factors, but it still offers workable verb classes: communication and certainty tend to take indicative; will, emotion, resistance, requests, doubt, and necessity tend to take subjunctive.
This page is a trigger table for when to use indicative vs subjunctive Spanish in subordinate clauses with que. For what the subjunctive mood is (and why it is not a tense), see Spanish subjunctive. Past-tense aspect splits are a different problem: preterite vs imperfect.
Trigger table: indicative vs subjunctive
| Main-clause job | Typical triggers | Mood in the que-clause | Example |
|---|---|---|---|
| Report / assert | decir, afirmar, comentar | Indicative | Dicen que está listo. |
| Certainty | saber, es evidente, es seguro | Indicative | Es evidente que lo sabe. |
| Wish / will | querer, desear, esperar | Subjunctive | Quiero que nieve. |
| Emotion | lamentar, alegrarse, dar rabia | Subjunctive | Lamento que digas eso. |
| Doubt / denial | dudar, negar | Subjunctive | Dudo que lo sepa. |
| Influence | pedir, aconsejar, prohibir | Subjunctive | Te aconsejo que lo hagas. |
| Necessity / possibility | es necesario, es posible | Subjunctive | Es posible que venga. |
Examples above follow the RAE Libro de estilo groupings and sample sentences. Regional variation still exists; the same manual notes that No sé si te gusta / guste patterns differ across Spain, the Río de la Plata, Mexico, and Caribbean areas.
The negation flip learners miss
Creo que viene keeps indicative because the speaker presents the complement as believed. No creo que venga switches to subjunctive because negation suspends that assertive force. The RAE Nueva gramática discusses negation as a classic mood inductor: No creo que lo viera, No es obvio que lo acepte. The flip is why a memorized list of "subjunctive verbs" fails when the same verb appears under no.
Relative-clause choice also changes meaning: Busco a una persona que lleva sombrero points to a specific person the speaker has in mind (indicative), while que lleve sombrero seeks anyone who fits the description (subjunctive). That contrast is in the same Libro de estilo section.
Copula choice is a separate Spanish decision tree; do not treat ser vs estar as a mood test.
What this page is not
It is not a full subjunctive conjugation table. Generating tense-by-tense forms needs a checked conjugator and tests, not memory dumps. It is also not a complete map of every conjunction: como, cuando, aunque, and conditional connectors each have their own mood rules in the Nueva gramática. Use the table above for the common que-clause decision, then verify edge cases against RAE entries rather than forum summaries.