Breakdown of Qualora il treno abbia un guasto, ci sarà un autobus sostitutivo.
un
a / an (masculine)
il treno
the train
avere
to have
c'è
there is / there are
Questions & Answers about Qualora il treno abbia un guasto, ci sarà un autobus sostitutivo.
Why is abbia in the subjunctive rather than the indicative ha?
The word qualora (meaning "in case" or "should") is a conditional conjunction that always triggers the subjunctive mood. Since we are talking about a possible event in the present or future, we use the present subjunctive abbia.
Can I just use se instead of qualora here?
Yes, but the grammar changes. Se is less formal, and in this type of highly realistic conditional sentence, it takes the indicative: se il treno ha un guasto. Qualora is more formal, translating closer to "should the train..." or "in the event that...", and strictly requires the subjunctive.
If I wanted to make the breakdown sound highly unlikely, could I use the imperfect subjunctive avesse?
You could, but you would have to change the second half of the sentence too. If you use the imperfect subjunctive qualora avesse (in the unlikely event it had), the main clause must use the conditional tense ci sarebbe (there would be) instead of the future tense ci sarà.