Breakdown of Il est peu probable que le volcan provoque une catastrophe.
être
to be
un
a / an (masculine)
il
it (impersonal subject)
peu
little, few
Questions & Answers about Il est peu probable que le volcan provoque une catastrophe.
Why does this sentence use the subjunctive when il est probable que normally takes the indicative?
The key is the word peu (little). While il est probable que expresses a strong likelihood and takes the indicative, il est peu probable que (it is unlikely that) expresses doubt or improbability. In French, expressing doubt or highlighting that something is unlikely always triggers the subjunctive.
The verb provoque looks exactly like the present indicative tense. How do we know it is the subjunctive?
For regular -er verbs like provoquer, the present subjunctive forms for je, tu, il/elle/on, and ils/elles are spelled identically to the present indicative. We know it is in the subjunctive here strictly because the grammatical structure il est peu probable que requires it.
The English translation says 'will cause,' but there is no future tense used in the French sentence. Why is that?
The French subjunctive mood does not have a future tense. Whenever a phrase requires the subjunctive, you use the present subjunctive to describe actions happening in either the present or the future.
Can I use improbable instead of peu probable to mean 'unlikely'?
Yes, you can say Il est improbable que. Just like il est peu probable que, it expresses a high level of doubt and therefore also requires the following verb to be in the subjunctive.