Breakdown of Si limpiaras el filtro, quizás la bujía no fallaría.
no
no, not
limpiar
to clean
fallar
to fail (machines, plans) / to crash
si
if
Questions & Answers about Si limpiaras el filtro, quizás la bujía no fallaría.
Why does quizás trigger the conditional tense (fallaría) here instead of the subjunctive or present indicative?
The verb fallaría is the result half of a hypothetical "if" sentence. When you set up a hypothetical condition with si plus the imperfect subjunctive (Si limpiaras...), the result must be in the conditional tense (fallaría). Adding quizás adds "perhaps" to the meaning, but the strict grammar rule of the "if/then" structure overrides the usual quizás rules you are learning in this lesson.
Could I use the subjunctive after quizás here and say quizás la bujía no falle?
You can, but you would have to change the first half of the sentence! If you say Si limpias el filtro... (present indicative), you are talking about a very real possibility: "If you clean the filter..." Then, you can finish with quizás la bujía no falle (present subjunctive: "maybe the spark plug won't fail"). You just can't mix the hypothetical "if you were to clean" (limpiaras) with the present subjunctive (falle).
Just as a refresher, why is the first verb limpiaras (imperfect subjunctive) instead of limpias (present)?
Using the imperfect subjunctive (limpiaras) makes the condition hypothetical or unlikely. It means "If you were to clean the filter" or "If you cleaned the filter" (implying the speaker thinks you haven't or might not). Using the present tense (limpias) would make it a highly likely, real-world condition: "If you clean the filter."