Breakdown of S'il y avait un danger, il faudrait que tu ailles dehors.
un
a / an (masculine)
tu
you (informal singular)
il y a
there is / there are
aller
to go
il
it (impersonal subject)
falloir
to be necessary / must (impersonal)
dehors
outside
si
if
que
that (introducing a clause)
le danger
the danger
Questions & Answers about S'il y avait un danger, il faudrait que tu ailles dehors.
Why is it ailles here instead of vas?
ailles is the present subjunctive form of aller (to go) for tu. We use the subjunctive here because the sentence uses il faudrait que (it would be necessary that), which is an expression of necessity and a classic subjunctive trigger.
I learned that il faut que triggers the subjunctive. Does it still trigger it when it is in the conditional (il faudrait que)?
Yes! Expressions of necessity still require the subjunctive regardless of the tense they are in. Whether it is il faut que (present), il fallait que (imparfait), or il faudrait que (conditional), the following verb must be in the subjunctive.
Why are we using the imperfect tense (avait) and the conditional tense (faudrait) together?
This is a hypothetical sentence. In French, to talk about a hypothetical present or future situation, you use si + imperfect tense (s'il y avait) + conditional tense (il faudrait). It maps closely to English: If there were a danger, it would be necessary to go outside.
Could I use devoir instead of il faudrait que to say 'you would have to'?
Absolutely. You could say tu devrais aller dehors (you would have to go / you should go outside). Both are very common and natural, but using il faudrait que is an excellent way to practice your subjunctive verbs!
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