Learn Spanish (Latin America): Es cierto que la propuesta es buena.

Wait, the lesson is about 'es + adjective + que' triggering the subjunctive. Why does this sentence use the indicative es instead of the subjunctive sea?

Impersonal expressions only trigger the subjunctive when they express a personal opinion, emotion, or doubt (like es importante que or es mejor que). Expressions that declare a certainty or established fact, like es cierto que (it is certain that), es verdad que, or es obvio que, use the normal indicative mood.

Is there any situation where I would use the subjunctive sea with this exact phrase?

Yes, if you make the phrase negative! Adding no changes the phrase from stating a certainty to expressing doubt or denial. For example, no es cierto que la propuesta sea buena (it is not true that the proposal is good) requires the subjunctive.

Can I say es verdad que instead of es cierto que?

Yes! Es verdad que is incredibly common and means the exact same thing (it is true that). Just like es cierto que, it states a fact, so it also uses the normal indicative mood for the second verb.

Why is the final word buena instead of bueno?